JP7572607B2 - Measurement equipment - Google Patents

Description

The present invention relates to measuring devices such as potentiometers (pH meters, redox potentiometers, ion meters, etc.), electrical conductivity meters, redox current measuring instruments (dissolved oxygen meters, residual chlorine meters, etc.), pressure meters, optical measuring instruments (turbidity meters, optical dissolved oxygen meters, etc.) that can be fitted with detachable sensors, such as water quality sensors, including potential difference measuring electrodes (pH electrodes, oxidation-reduction potential difference measuring electrodes (ORP electrodes), ion electrodes, etc.), electrical conductivity cells, oxidation-reduction current measuring electrodes (dissolved oxygen electrodes, residual chlorine electrodes, etc.), pressure sensors, and optical sensors (turbidity sensors, optical dissolved oxygen sensors, etc.).

Conventionally, there are measuring devices such as pH meters, electrical conductivity meters, and dissolved oxygen meters that have detachable sensors, such as water quality sensors such as pH electrodes, electrical conductivity cells, and dissolved oxygen electrodes. The sensors are detached from the measuring devices when they reach the end of their life or need to be replaced due to a malfunction.

Patent Document 1 discloses a measuring device that uses recognition means provided in the device body to recognize identification information stored in a memory that serves as identification means provided in a probe equipped with a sensor such as a pH electrode, thereby identifying the probe (i.e., identifying the sensor). This makes it possible to automatically switch between functions for multiple different measurement items according to the type of probe (i.e., the type of sensor).

JP 2005-114697 A

Sensors, such as the water quality sensor mentioned above, are usually manufactured and provided to users under controlled conditions so that they meet the performance guaranteed by the manufacturer. However, non-genuine sensors (so-called non-standard, non-genuine, counterfeit, etc.) that do not meet the performance guaranteed by the manufacturer may be available on the market. If such a non-genuine sensor is connected to a measuring device and used, for example, measurement accuracy may decrease under certain conditions, resulting in erroneous measurements, which would not be an issue if the sensor was a genuine sensor whose performance is guaranteed by the manufacturer.

As mentioned above, measuring devices with a function for identifying sensors have been proposed in the past, but no measures have been disclosed for when a non-genuine sensor is connected to the measuring device. Depending on how the user acquired the sensor or the situation (purpose) and conditions in which the sensor is used, it may not be desirable to simply uniformly prohibit the use of non-genuine sensors. As a measure against non-genuine sensors, it is necessary to enable the user to recognize that a non-genuine sensor is being used and to fully anticipate the consequences of using a non-genuine sensor, and then to allow the use of non-genuine sensors.

Therefore, the object of the present invention is to provide a measuring device that can safely perform measurements with the desired accuracy by preventing unexpected measurement results that may occur due to the use of non-genuine sensors.

The above object is achieved by the measurement device according to the present invention. In summary, the present invention is a measurement device in which a sensor according to a measurement object can be attached and detached, the measurement device having a control means for controlling measurement using the sensor, the control means being capable of executing an identification process for determining whether the connected sensor is genuine or not based on acquiring identification information from the sensor when the sensor is connected, and a switching process for switching the control between a first mode corresponding to the case where the sensor is genuine and a second mode corresponding to the case where the sensor is not genuine according to the result of the identification process, the control means executing a path process for determining whether predetermined path information has been acquired from an input means other than the sensor when switching the control to the second mode, and enabling measurement when the predetermined path information has been acquired according to the result of the path process, and prohibiting measurement when the predetermined path information has not been acquired .
According to another aspect of the present invention, there is provided a measuring device in which a sensor corresponding to an object to be measured can be attached and detached, the measuring device having a control means for controlling measurement using the sensor, the control means being capable of executing an identification process for determining whether the connected sensor is genuine or not based on obtaining identification information from the sensor when the sensor is connected, and a switching process for switching the control between a first mode corresponding to the case where the sensor is genuine and a second mode corresponding to the case where the sensor is not genuine depending on the result of the identification process, and the control means, when switching the control to the second mode, executes a process for obtaining, from an input means separate from the sensor, predetermined information regarding the measurement that can be obtained from the sensor in the first mode.
According to another aspect of the present invention, there is provided a measuring device in which a sensor corresponding to an object to be measured can be attached and detached, the measuring device having a control means for controlling measurement using the sensor, the control means being capable of executing an identification process for determining whether the connected sensor is genuine or not based on obtaining identification information from the sensor when the sensor is connected, and a switching process for switching the control between a first mode corresponding to the case where the sensor is genuine and a second mode corresponding to the case where the sensor is not genuine depending on the result of the identification process, and the control means is configured not to execute processing related to a function that uses the detection result of a temperature detection element provided in the sensor in the second mode, which is a part of the functions that can be executed in the first mode.
According to another aspect of the present invention, a measuring device to which a sensor according to an object to be measured can be attached and detached has a control means for controlling measurement using the sensor, and the control means is capable of executing an identification process for determining whether the connected sensor is genuine or not based on acquisition of identification information from the sensor when the sensor is connected, and a switching process for switching the control between a first mode corresponding to the case where the sensor is genuine and a second mode corresponding to the case where the sensor is not genuine, depending on the result of the identification process, and the control means is configured to control the sensor by communication with the sensor. A measuring device is provided which acquires identification information attached to an identification means provided on the sensor, the identification means is configured with a storage medium, the identification information includes information of a specific identification code predetermined according to the type of the sensor, the storage medium stores manufacturing time information indicating the time when the sensor was manufactured and connection time information indicating the time when the sensor was first connected to the measuring device, and the control means determines that the sensor is genuine when the identification code satisfies predetermined conditions and further when the relationship between the manufacturing time information and the connection time information satisfies predetermined conditions.

The present invention makes it possible to safely perform measurements with the desired accuracy by preventing unexpected measurement results from occurring due to the use of non-genuine sensors.

FIG. 1 is a schematic perspective view showing an overall configuration of a measurement device. FIG. 2 is a functional block diagram of a measurement device to which a probe for measuring pH is connected. FIG. 2 is a functional block diagram of a probe for measuring electrical conductivity and a probe for measuring dissolved oxygen. 11 is a flowchart illustrating an identification process and a measurement control switching process. 13 is a flowchart showing an example of measurement control in the case of a genuine product. 13 is a flowchart showing an example of measurement control when the product is not genuine. 13 is a flowchart showing another example of measurement control when the product is not genuine. 13 is a flowchart showing another example of measurement control when the product is not genuine. 13 is a flowchart showing another example of measurement control when the product is not genuine. FIG. 13 is a schematic diagram showing an example of displaying measurement results. 11A and 11B are schematic diagrams showing examples of error and warning displays; 13 is a schematic diagram showing an example of an input screen for measurement information and path information; FIG.

The measurement device according to the present invention will be described in more detail below with reference to the drawings.

[Example 1]
1. Configuration of the Measuring Apparatus Fig. 1 is a schematic perspective view showing the overall configuration of a measuring apparatus 1 according to the present embodiment. Fig. 2 is a functional block diagram of the measuring apparatus 1 according to the present embodiment.

In this embodiment, the measuring device 1 has a device body 2 and a probe 3 that can be attached to and detached from the device body 2. In this embodiment, the measuring device 1 can be used interchangeably with a pH measuring probe (also called a "pH probe" here) 3A equipped with a pH electrode that is a potential difference measuring electrode as a sensor, a conductivity measuring probe (also called an "EC probe" here) 3B (FIG. 3(a)) equipped with an electrical conductivity cell as a sensor, and a dissolved oxygen measuring probe (also called a "DO probe" here) 3C (FIG. 3(b)) equipped with a dissolved oxygen electrode that is an oxidation-reduction current measuring electrode as a sensor. When elements that are commonly provided in the pH probe 3A, EC probe 3B, and DO probe 3C are generally described, the suffixes A, B, and C that indicate that the element belongs to any of the probes may be omitted. FIGS. 1 and 2 each show a state in which the pH probe 3A is connected to the device body 2 as an example of the probe 3.

In this embodiment, the probe 3 has a sensor unit 4 and a measurement unit 5. The sensor unit 4 has a measurement section 41 according to the measurement target. For example, in the case of the pH probe 3A, the sensor unit 4A is configured with an elongated pH electrode having a pH-sensitive part such as a glass sensitive membrane constituting the measurement section 41A at the tip part at the bottom of the figure. The sensor unit 4 also has a sensor memory 42, which is a storage medium constituting the identification means described in detail later. On the other hand, the measurement unit 5 has a measurement circuit 51 that converts an analog signal acquired from the sensor unit 4 into a digital signal indicating the measurement result of the sensor unit 4. For example, in the case of the pH probe 3A, the measurement circuit 51 is a measurement circuit 51A for pH measurement, which is a measurement circuit for measuring potential difference. The measurement unit 5 is provided on the base end side opposite to the tip side of the sensor unit 4. The measurement unit 5 also has a probe side connector 52 connected to the measurement circuit 51 via a cable 55 for detachably connecting the probe 3 to the device main body 2. In this embodiment, the sensor unit 4 constitutes a sensor that can be attached to and detached from the measurement device 1.

As shown in FIG. 3(a), the EC probe 3B has a sensor unit 4B including an elongated electrical conductivity cell including a measuring section 41B and a sensor memory 42B, and a measurement unit 5C. The measurement unit 5C of the EC probe 3B includes a measurement circuit 51B for measuring electrical conductivity, and a probe-side connector 52B connected to the measurement circuit 51B via a cable 55B.

As shown in FIG. 3(b), the DO probe 3C has a sensor unit 4C that includes an elongated dissolved oxygen electrode that includes a measuring section 41C and a sensor memory 42C, and a measuring unit 5C. The measuring unit 5C of the DO probe 3C includes a measuring circuit 51C for measuring dissolved oxygen, which is a measuring circuit for measuring redox current, and a probe side connector 52C that is connected to the measuring circuit 51C via a cable 55C.

The probe 3 will be further described. In this embodiment, the sensor unit 4 is detachable from the measurement unit 5. The sensor unit 4 has a first inter-unit connector (sensor unit side connector) 44, and the measurement unit 5 has a second inter-unit connector (measurement unit side connector) 54 that is detachably connected to the first inter-unit connector 44. In this way, in this embodiment, the sensor unit 4 is detachable from the measurement unit 5, and therefore the sensor unit 4 is detachable from the measurement device 1.

The sensor unit 4 has a first board (sensor unit board) 43, which is a printed circuit board, adjacent to its base end, and the first board 43 is provided with a sensor memory 42 and a first inter-unit connector 44. The measurement unit 5 has a second board (measurement unit board) 53, which is a printed circuit board, and the second board 53 is provided with a measurement circuit 51 and a second inter-unit connector 54. The first inter-unit connector 44 is arranged in the sensor unit 4 so as to be exposed from the base end of the sensor unit 4, which is roughly elongated and cylindrical. The measurement unit 5 has a recess 8 into which the base end of the sensor unit 4 is inserted, and the second inter-unit connector 54 is arranged in the measurement unit 5 so as to be exposed in this recess 8. The base end of the sensor unit 4 is inserted (fitted) into the recess 8 of the measurement unit 5, and the first and second inter-unit connectors 44 and 54 are connected, so that the sensor unit 4 and the measurement unit 5 are integrated to form the probe 3. In this embodiment, the sensor unit 4 is slid and fitted into the recess 8 of the measurement unit 5. In addition, the wiring drawn from the measurement circuit 51 of the measurement unit 5 is bundled as a cable 55 and connected to the probe side connector 52. The probe 3 is detachably connected to the main body side connector 22 provided on the device main body 2 by the probe side connector 52 via the cable 55.

As described above, the first substrate 43 of the sensor unit 4 is provided with the first inter-unit connector 44 and the sensor memory 42. For example, in the case of the pH probe 3A, the sensor unit 4A is provided with a measurement electrode (internal electrode) 61 and a comparison electrode (internal electrode) 62 that constitute the measurement section 41A together with a pH-sensitive section such as a glass sensitive membrane, and a temperature sensor (temperature detection element) 63 for temperature compensation. The measurement electrode (internal electrode) 61, the comparison electrode (internal electrode) 62, the temperature sensor 63 for temperature compensation, and the sensor memory 42 provided on the first substrate 43 are each connected to a corresponding one of a plurality of pins provided on the first inter-unit connector 44.

The second board 53 of the measurement unit 5 is provided with a second inter-unit connector 54, a measurement circuit 51, a CPU 56, a communication driver 57, and a measurement unit memory 58, which is a storage medium. For example, in the case of the pH probe 3A, the measurement circuit 51 is a measurement circuit 51A for pH measurement. The measurement circuit 51 is provided with an amplifier and an A/D converter. The amplifier appropriately amplifies the analog signal (pH measurement signal, temperature measurement signal, etc.) acquired from the sensor unit 4. A plurality of amplifiers may be provided corresponding to the signal (pH measurement signal, temperature measurement signal, etc.) input to the measurement unit 5. The A/D converter converts the analog signal amplified by the amplifier into a digital signal indicating the measurement result of the sensor unit 4. The CPU 56 of the measurement unit 5 comprehensively controls the processing (operation) in the probe 3. In particular, the CPU 56 of the measurement unit 5 processes (corrects, etc.) the digital signal acquired from the A/D converter to obtain the measurement result (measurement value) of the sensor unit 4. The communication driver 57 controls the transmission of digital signals between the CPU 56 of the measurement unit 5 and the device body 2. The measurement unit memory 58 stores procedures (programs) and data for controlling the processing in the probe 3. In particular, in this embodiment, the measurement unit memory 58 stores procedures and data for calculating and outputting measurement results (pH value, temperature value, etc.). In this embodiment, a non-volatile memory (electrically erasable and writable read-only memory) is used as the measurement unit memory 58. As the measurement unit memory 58, a non-volatile memory, a flash memory, a RAM with battery backup, an EPROM, a one-time ROM, etc. can be used. The multiple pins of the second inter-unit connector 54 are each connected to a corresponding pin among the multiple pins of the first inter-unit connector 44. The measurement circuit (pH measurement amplifier, temperature measurement amplifier, etc.) 51, the CPU 56, etc. provided on the second board 53 are connected to the corresponding pin among the multiple pins of the second inter-unit connector 54 provided on the second board 53.

As shown in FIG. 3(a), in the case of the EC probe 3B, the sensor unit 4B is provided with a platinum black electrode 64 for detection and a platinum black electrode 65 for voltage application, which constitute the measurement section 41B, and a temperature sensor 63 for temperature compensation. The platinum black electrode 64 for detection, the platinum black electrode 65 for voltage application, the temperature sensor 63 for temperature compensation, and the sensor memory 42B provided on the first board 43B are each connected to corresponding pins among a plurality of pins provided on the first inter-unit connector 44B provided on the first board 43B. In addition, in the case of the EC probe 3B, the measurement circuit 51 is a measurement circuit 51B for measuring electrical conductivity. The measurement circuit 51B for measuring electrical conductivity is provided with a voltage application section in addition to the above-mentioned amplifier and A/D converter. The measurement circuit (electrical conductivity measurement amplifier, temperature measurement amplifier, voltage application unit, etc.) 51B and CPU 56 provided on the second board 53B are connected to corresponding pins among the multiple pins provided on the second inter-unit connector 54B provided on the second board 53B.

As shown in FIG. 3B, in the case of the DO probe 3C, the sensor unit 4C is provided with the working electrode 66 and the counter electrode 67 constituting the measurement section 41C, and the temperature sensor 63 for temperature compensation. The working electrode 66, the counter electrode 67, the temperature sensor 63 for temperature compensation, and the sensor memory 42C provided on the first substrate 43C are each connected to a corresponding pin among the multiple pins provided on the first inter-unit connector 44C provided on the first substrate 43C. In the case of the DO probe 3C, the measurement circuit 51 is a measurement circuit 51C for measuring dissolved oxygen. In addition to the above-mentioned amplifier and A/D converter, the measurement circuit 51C for measuring dissolved oxygen is provided with a voltage application section. The measurement circuit (amplifier for measuring dissolved oxygen, amplifier for measuring temperature, voltage application section, etc.) 51C and the CPU 56 provided on the second substrate 53C are connected to a corresponding pin among the multiple pins provided on the second inter-unit connector 54C provided on the second substrate 53C.

In this embodiment, the sensor unit 4A of the pH probe 3A is a composite electrode in which a measurement electrode (glass electrode) and a comparison electrode are integrated. The measurement circuit 51A for pH measurement provided in the measurement unit 5A of the pH probe 3A detects the electromotive force generated in the glass sensitive film by measuring the potential difference between the two electrodes with a voltmeter.

In this embodiment, the sensor unit 4B of the EC probe 3B is an AC two-pole type that uses platinum black electrodes. The measurement circuit 51B for measuring electrical conductivity that is provided in the measurement unit 5B of the EC probe 3B applies an AC voltage between the two electrodes, and measures the current that flows at that time with an ammeter to detect the impedance.

In this embodiment, the sensor unit 4C of the DO probe 3C is a diaphragm-type polarographic electrode having a working electrode and a counter electrode in the sensor unit 4C separated by an oxygen gas permeable diaphragm. The measurement circuit 51C for measuring dissolved oxygen provided in the measurement unit 5C of the DO probe 3C detects a diffusion current proportional to the dissolved oxygen by applying a DC voltage between the two electrodes and measuring with an ammeter the current that flows when oxygen that has permeated the diaphragm is reduced at the working electrode.

Next, the device body 2 will be further described. In this embodiment, the device body 2 has a body side connector 22 that can be connected by replacing the probe side connector 52 of each of the pH probe 3A, EC probe 3B, and DO probe 3C, which are probes 3 having different measurement circuits 51. The device body 2 also includes a digital signal processing circuit 23 as a digital signal processing means, a probe power supply circuit 24 as a probe power supply means, a probe presence/absence identification circuit 25 as a probe presence/absence identification means, a CPU 21 as a control means, an operation unit 26 such as an operation key as an operation means, a display unit 27 such as a liquid crystal display as a display means, a main body memory 28 as a storage medium, and a power supply unit 29. The digital signal processing circuit 23, the probe power supply circuit 24, the probe presence/absence identification circuit 25, the operation unit 26, the display unit 27, and the main body memory 28 are each connected to the CPU 21 of the device body 2. Each part of the device body 2 operates with power supplied from the power supply unit 29. The multiple pins of the main body side connector 22 are each connected to a corresponding circuit among the digital signal processing circuit 23, the probe power supply circuit 24, and the probe presence/absence identification circuit 25. The multiple pins of the probe side connector 52 are each connected to a corresponding pin among the multiple pins of the main body side connector 22.

The digital signal processing circuit 23 acquires a digital signal from the probe 3 and transmits it to the CPU 21 of the device body 2 for processing to output the measurement result, or for identification processing and measurement control switching processing, which will be described in detail later. The probe power supply circuit 24 supplies power to the probe 3. Each part of the probe 3 operates with the power supplied from the probe power supply circuit 24. The probe presence/absence identification circuit 25 identifies the presence or absence of the probe 3 based on the presence or absence of the pin for identifying the presence or absence of the probe in the probe side connector 52 connected to the pin for identifying the presence or absence of the probe in the main body connector 22, and transmits a signal indicating the identification result to the CPU 21 of the device body 2. The CPU 21 of the device body 2 comprehensively controls the processing (operation) in the device body 2. In particular, in this embodiment, the CPU 21 of the device body 2 performs processing to output the measurement result of the probe 3 (pH value, electrical conductivity value, dissolved oxygen concentration value, temperature value, etc.) based on the digital signal acquired from the probe 3. The operation unit 26 accepts instructions from the user (operator) such as starting and stopping the measurement and inputting various settings, and transmits them to the CPU 21 of the device body 2. The display unit 27 displays the measurement results and displays a setting screen for various settings under the control of the CPU 21 of the device body 2. The device body 2 may have a touch panel having the functions of an operation means (operation unit) and a display means (display unit). The main body memory 28 stores procedures and data for controlling the processing in the device body 2. The main body memory 28 stores procedures and data for outputting (displaying, etc.) the measurement results (pH value, electrical conductivity value, dissolved oxygen concentration value, temperature value, etc.) according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2, and procedures and data for performing setting operations by the operation unit 26 according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2. In particular, in this embodiment, the main body memory 28 stores procedures and data for performing an identification process and a measurement control switching process, which will be described in detail later. Furthermore, the main body memory 28 can also store measurement results. In this embodiment, an EPROM is used as the main memory 28. Non-volatile memory, flash memory, RAM with battery backup, EPROM, one-time ROM, etc. can also be used as the main memory 28.

2. Identification Means and Recognition Means In this embodiment, the sensor unit 4 is provided with a sensor memory 42, which is a storage medium constituting the identification means. In this embodiment, a non-volatile memory is used as the sensor memory 42. As the storage medium constituting the identification means, a non-volatile memory, a flash memory, a RAM with battery backup, an EPROM, a one-time ROM, a CPU with memory, etc. may be used. Note that the identification means is not limited to being configured with a storage medium. The identification means may be configured with the above-mentioned storage medium; physical quantity or state changing means such as a switch, an analog switch, a resistor, or a capacitor; physical quantity generating means such as a voltage generator, a current generator, or a light generator; a physical shape change of the sensor unit 4; or a barcode.

On the other hand, in this embodiment, the device body 2 is provided with a recognition means (reading means) for reading and recognizing the information attached to the identification means. In this embodiment, the CPU 21 provided in the device body 2 has the function of the recognition means for reading and recognizing the information stored in the sensor memory 42. Here, the recognition means recognizing the information attached to the identification means is not limited to the recognition means provided in the device body 2 directly reading and recognizing the information attached to the identification means. For example, in a configuration in which the measurement device 1 has a sensor unit 4, a measurement unit 5, and a device body 2 as in this embodiment, it also includes the recognition means provided in the measurement unit 5 reading (and recognizing) the information attached to the identification means, and the recognition means provided in the device body 2 recognizing the information indicating the reading result (and the recognition result). In addition, the control means provided in the measurement unit 5 can also perform processing based on the recognition result by the recognition means provided in the measurement unit 5. That is, in the present embodiment, in a configuration in which the measuring device 1 has a sensor unit 4, a measuring unit 5, and a device main body 2, the recognition means may be provided in at least one of the measuring unit 5 and the device main body 2. In addition, the recognition means may correspond to the above-mentioned various identification means and may be capable of reading and recognizing information attached to the identification means. For example, if the identification means is the physical quantity or state changing means, the recognition means may be a means for reading and recognizing the change (difference) in the physical quantity or state, if the identification means is the physical quantity generating means, the recognition means may be a means for receiving and recognizing the physical quantity, if the identification means is a physical shape change (difference) of the sensor unit 4, the recognition means may be a means for reading and recognizing the physical shape change, and if the identification means is the barcode, the recognition means may be a means for reading and recognizing the barcode.

However, in terms of cost, ease of information transmission, and the amount of information that can be attached, the identification means is preferably a storage medium made up of electronic memory. In this embodiment, the storage medium constituting the identification means and the recognition means are capable of wired communication, but the storage medium constituting the identification means may be a non-contact type capable of wireless communication with the recognition means.

The identification means is provided with identification information related to the sensor unit 4. In particular, in this embodiment, the identification information includes information of a specific identification code that is predetermined according to the type of the sensor unit 4 (measurement items, model, etc.), which indicates that the sensor unit 4 is a genuine product. The identification code may be, for example, character string information such as "123456" or "a1b2". Here, the identification information may include information on the type of the sensor unit 4 (measurement items, model, etc.). For example, the identification information may be information on an identification code that is substantially composed of only information on the type of the sensor unit 4 (measurement items, model, etc.) according to a predetermined description method, or that includes information on the type of the sensor unit 4 (measurement items, model, etc.) as a part of the information. In addition, the identification code is not made public. Furthermore, the identification information may be encrypted using a predetermined encryption method. If the identification information is encrypted using a predetermined encryption method, the recognition means may read and recognize the identification information by decrypting it using a predetermined decryption method corresponding to the encryption method.

3. Basic Operation Next, a basic operation of the measurement device 1 when the probe 3 in this embodiment is replaced and connected to the device main body 2 will be described.

In this embodiment, the CPU 21 of the device body 2 automatically switches the process of outputting the measurement results according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2 based on the identification information stored in the sensor memory 42. Also, in this embodiment, the CPU 21 of the device body 2 automatically switches the function of the operation unit 26 provided on the device body 2 according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2 based on the identification information stored in the sensor memory 42.

For example, when the probe-side connector 52A of the pH probe 3A is connected to the main body-side connector 22 of the device main body 2, each pin of the probe-side connector 52A is connected to each pin of the main body-side connector 22, and it becomes possible to exchange digital signals between the pH probe 3A and the device main body 2, to supply power from the device main body 2 to the pH probe 3A, and to identify the presence or absence of the pH probe 3A. The CPU 21 of the device main body 2, which functions as a recognition means, reads the identification information stored in the sensor memory 42A of the sensor unit 4A of the pH probe 3A as an identification means through the measurement unit 5A of the pH probe 3A, and recognizes that the probe 3 connected to the device main body 2 is the pH probe 3A (i.e., the sensor unit 4 connected to the measurement device 1 is the sensor unit 4A for pH measurement). When the CPU 21 of the device main body 2 recognizes that the pH probe 3A is connected, it switches the display on the display unit 27 to a display for pH measurement as shown in FIG. 10(a), and displays the pH value, temperature value, etc. The process of outputting the measurement results may be at least one of the following: displaying the measurement results on the display unit 27; printing and outputting the measurement results on a printer provided in or connected to the device body 2; outputting a signal related to the measurement results to an external device for display on a display means of an external device such as a personal computer communicably connected to the device body 2; or outputting a signal related to the measurement results to record the measurement results in a storage medium provided in or connected to the device body 2 or the external device. The CPU 21 of the device body 2 switches the functions of the operation unit 26, such as the setting operation by the user on the operation unit 26, to functions adapted to pH measurement, such as starting and stopping pH measurement and starting and stopping the calibration operation of the pH electrode.

Similarly, when the EC probe 3B is connected to the device body 2, the CPU 21 of the device body 2 reads the identification information stored in the sensor memory 42B via the measurement unit 5B and recognizes that the EC probe 3B has been connected (i.e., that the sensor unit 4B for measuring electrical conductivity has been connected). The CPU 21 of the device body 2 then switches the display on the display unit 27 to a display for measuring electrical conductivity (electrical conductivity value, temperature value, etc.) as shown in FIG. 10(b), and switches the function of the operation unit 26 to a function for measuring electrical conductivity.

Similarly, when the DO probe 3C is connected to the device body 2, the CPU 21 of the device body 2 reads the identification information stored in the sensor memory 42C via the measurement unit 5C and recognizes that the DO probe 3C has been connected (i.e., that the sensor unit 4C for measuring dissolved oxygen has been connected). The CPU 21 of the device body 2 then switches the display on the display unit 27 to a display for measuring dissolved oxygen (dissolved oxygen concentration value, temperature value, etc.) as shown in FIG. 10(c), and switches the function of the operation unit 26 to a function for measuring dissolved oxygen.

4. Identification Processing and Measurement Control Switching Processing Next, the identification processing and measurement control switching processing in this embodiment will be described.

In this embodiment, when the sensor unit 4 is connected to the measuring device 1, the CPU 21 of the device body 2 can execute an identification process to determine whether the connected sensor unit 4 is genuine based on the identification information obtained from the sensor unit 4, and a switching process (measurement control switching process) to switch the control of the measurement using the sensor unit 4 (measurement control) between a first mode corresponding to the case where the sensor unit 4 is genuine and a second mode corresponding to the case where the sensor unit 4 is not genuine, depending on the result of the identification process. Here, the case where the sensor unit 4 is connected to the measuring device 1 includes a case where the sensor unit 4 is connected to the measuring unit 5 connected to the device body 2, a case where the probe 3 formed by connecting the sensor unit 4 to the measuring unit 5 is connected to the device body 2, etc.

Figure 4 is a flow chart showing an outline of the operation of the measuring device 1 when the sensor unit 4 is connected to the measuring device 1. Here, the case where the probe 3 formed by connecting the sensor unit 4 to the measurement unit 5 is connected to the device main body 2 will be mainly described as an example.

First, the CPU 21 of the device body 2 reads the identification result of the probe presence/absence identification circuit 25, determines whether or not the probe 3 is connected to the device body 2, and if it determines that the probe 3 is connected, reads the identification information from the sensor memory 42 via the measurement unit 5 (S101). This operation can be performed when the probe 3 is connected to the device body 2, when the power supply of the measurement device 1 is turned on after the probe 3 is connected to the device body 2, or every time the power supply of the measurement device 1 is turned on.

Next, the CPU 21 of the device body 2 executes an identification process to determine whether the sensor unit 4 connected to the measuring device 1 is genuine based on the identification information read from the sensor memory 42 (S102). In this embodiment, the CPU 21 of the device body 2 determines whether a predetermined specific identification code as the identification information read from the sensor memory 42 satisfies a predetermined condition stored in the main memory 28 in the identification process, and determines that the sensor unit 4 is genuine if the predetermined condition is satisfied (typically, if the identification code stored in the sensor memory 42 matches the identification code for verification stored in the main memory 28). In other words, the CPU 21 of the device body 2 determines whether a proper identification code has been obtained from the sensor memory 42, and if so, determines that the sensor unit 4 is genuine. Furthermore, if the CPU 21 of the device main body 2 is able to read the identification code but does not satisfy a predetermined condition (typically, the identification code stored in the sensor memory 42 does not match the identification code for verification stored in the main body memory 28), or if the identification code cannot be read, it determines that the sensor unit 4 is not genuine. Here, cases where the identification code cannot be read include cases where the sensor memory 42 is provided but the identification information is not stored in a predetermined description format and therefore cannot be read (recognized), cases where the sensor memory 42 itself is not provided, etc.

Next, if the CPU 21 of the device body 2 determines in S102 that the sensor unit 4 is genuine, it executes a measurement control switching process to switch the measurement control to a first mode that corresponds to the case where the sensor unit 4 is genuine (S103).

5 is a flow chart showing an outline of an example of the operation (measurement control) when switching to the first mode. When switching to the first mode in S103 of FIG. 4, the CPU 21 of the device body 2 automatically switches the process of outputting the measurement result according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2 based on the identification information as described above (S201), and automatically switches the function of the operation unit 26 provided in the device body 2 according to the probe 3 (i.e., the sensor unit 4) connected to the device body 2 (S202). For example, when the pH probe 3A is connected to the device body 2, the CPU 21 of the device body 2 switches the functions such as the display on the display unit 27 and the setting operation on the operation unit 26 to pH measurement (FIG. 10(a)). Similarly, when the EC probe 3B is connected, the display on the display unit 27 and the functions of the operation unit 26, such as the setting operation, are switched to electrical conductivity measurement (Figure 10 (b)), and when the DO probe 3C is connected, the display on the display unit 27 and the functions of the operation unit 26, such as the setting operation, are switched to dissolved oxygen measurement (Figure 10 (c)).

In this embodiment, in addition to the identification information, the sensor memory 42 stores information such as calibration data and correction values necessary for converting the output of the sensor unit 4 into a measured value (also referred to as "measurement information" here). When switching to the first mode in S103 of FIG. 4, the CPU 21 of the device body 2 instructs the CPU 56 of the measurement unit 5 to read the measurement information from the sensor memory 42 (S203) and store the read measurement information in the measurement unit memory 58 (or the storage unit in the CPU 56 of the measurement unit 5) (S204). Almost simultaneously with the processing of S201 to S204, the CPU 56 of the measurement unit 5 reads a digital signal corresponding to the output of the sensor unit 4 generated by the measurement circuit 51, calculates a measurement value (pH value, electrical conductivity value, dissolved oxygen concentration value, temperature value, etc.) using the above-mentioned measurement information, and transmits a digital signal indicating the measurement value to the CPU 21 of the device body 2. The CPU 21 of the device body 2 generates a signal for displaying the measurement value on the display unit 27 in response to the digital signal acquired from the measurement unit 5, and can display the measurement value on the display unit 27. In this way, if the sensor unit 4 is a genuine product, when the probe 3 is connected to the device body 2, measurement using the sensor unit 4 can be performed substantially immediately without requiring any special operation by the user.

Examples of the measurement information include the following:

(I) For example, in the case of the pH probe 3A or DO probe 3C, it is necessary to calibrate the characteristics of the probe 3 (more specifically, the sensor unit 4) using a standard solution or the like before use, and to calculate and correct the measured value based on the calibration result. Therefore, in addition to the identification information, it is possible to store calibration data at the time of inspection of the sensor unit 4 as measurement information in the sensor memory 42. For example, the sensor memory 42 stores identification information at the time of manufacturing the sensor unit 4, and stores calibration data as measurement information at the time of inspection of the sensor unit 4. Here, the CPU 21 of the device main body 2 can determine whether the sensor unit 4 is the sensor unit 4 used last time based on the identification information. Then, if the CPU 21 of the device main body 2 determines that the sensor unit 4 is the sensor unit 4 used last time, it can use the calibration data used last time that was previously read from the sensor memory 42 and stored in the measurement unit memory 58 (or the memory unit in the CPU 56 of the measurement unit 5). On the other hand, if the CPU 21 of the device body 2 determines that the sensor unit 4 is not the sensor unit 4 used last time, it can read the calibration data from the sensor memory 42 and store it in the measurement unit memory 58 (or the storage unit in the CPU 56 of the measurement unit 5). Then, the measurement unit 5 can calculate and correct the measurement value based on the calibration data stored in the measurement unit memory 58 (or the storage unit in the CPU 56 of the measurement unit 5). The CPU 21 of the device body 2 may be configured to control writing of information related to the sensor unit 4, such as new calibration data, to the sensor memory 42 directly or via the measurement unit 5. For example, in the pH probe 3A and the DO probe 3C, calibration data is obtained according to a predetermined calibration procedure using a standard solution as necessary. For example, the sensor unit 4 is calibrated before the first measurement using the sensor unit 4 after replacing the sensor unit 4, or periodically. In this case, the CPU 21 of the device body 2 can control writing (updating) the acquired new calibration data to the sensor memory 42.

(II) For example, the EC probe 3B requires information on the cell constant, which is a correction value for correcting its sensitivity. Therefore, it is possible to store the cell constant in advance in the sensor memory 42 as measurement information in addition to the identification information. For example, the sensor memory 42 stores the identification information when the sensor unit 4 is manufactured, and stores the cell constant as measurement information when the sensor unit 4 is inspected. The measurement unit 5 can then calculate and correct the measurement value based on the cell constant read from the sensor memory 42 and stored in the measurement unit memory 58 (or the memory section of the CPU 56 of the measurement unit 5).

(III) As described in detail later, the potential difference measuring probe 3 includes a sensor unit 4 for pH measurement equipped with a pH electrode, and a sensor unit 4 for ion measurement equipped with an ion electrode (ion electrode) other than a pH electrode. For example, when the sensor unit 4 is an ion measurement sensor unit 4 equipped with an ion electrode, it is possible to store the ion valence in the sensor memory 42 in advance as measurement information. Then, the measurement unit 5 can automatically set the calculation processing of the measurement value based on the ion valence read from the sensor memory 42 and stored in the measurement unit memory 58 (or the memory unit of the CPU 56 of the measurement unit 5). The same applies to sensors with other electrode coefficients (e.g., a residual chlorine electrode). Here, the electrode coefficient of the residual chlorine electrode refers to a coefficient that is multiplied by the measurement value of the residual chlorine electrode so that the measurement value of the DPD method and the measurement value of the residual chlorine electrode match (measurement value of the DPD method = measurement value of the residual chlorine electrode x electrode coefficient).

(IV) For example, in a thermistor thermometer, a compensation resistor is inserted into the thermistor to improve the accuracy or compatibility of temperature measurement, or an element with the same characteristics is selected and used. Therefore, when the sensor unit 4 is equipped with a thermistor (a temperature sensor for temperature compensation or a temperature sensor for temperature measurement), the sensor memory 42 can store thermistor characteristic data as measurement information, such as B constant, nominal resistance value, temperature table, etc. Then, the measurement unit 5 can calculate and correct the measured value based on this data read from the sensor memory 42 and stored in the measurement unit memory 58 (or the memory section of the CPU 56 of the measurement unit 5). The same applies to a measurement device that uses other resistance-type temperature sensor electrodes, such as platinum resistance thermometers, instead of the thermistor electrodes as the temperature detection elements.

Returning to the flowchart of FIG. 4, if the CPU 21 of the device main body 2 determines in S102 that the sensor unit is not genuine, it executes a measurement control switching process to switch the measurement control to a second mode that corresponds to the case where the sensor unit 4 is not genuine (S104).

Figure 6 is a flow chart showing an outline of an example of the operation (measurement control) when switching to the second mode. When switching to the second mode in S104 of Figure 4, the CPU 21 of the device body 2 can perform a process to prohibit measurement using a sensor unit 4 that is not genuine (S301). Then, the CPU 21 of the device body 2 can perform a process to display information on the display unit 27 indicating that the sensor unit 4 is not genuine and that measurement cannot be performed using the sensor unit 4 (S302).

Examples of the process for prohibiting measurement in S301 include the following. For example, the CPU 56 of the measurement unit 5 can be instructed not to perform the process for obtaining a measurement value. Also, when a measurement unit 5 that applies a voltage to the sensor unit 4, such as a measurement unit 5 for measuring redox current, is used, the application of voltage from the measurement unit 5 to the sensor unit 4 can be stopped (or prohibited). Also, in a measurement device 1 capable of measuring multiple different measurement items as in this embodiment, it is possible not to switch at least one of the display of the display unit 27 or the function of the operation unit 26 according to the measurement item.

As an example of the display in S302, as shown in FIG. 11(a), an error message such as "The sensor is not genuine. Measurement cannot be performed using a non-genuine sensor" can be displayed. In this way, prohibiting measurement using a non-genuine sensor unit 4 is effective in cases where genuine sensor units 4 require relatively strict product management, and the measurement results when a non-genuine sensor unit 4 is used are unpredictable, or there is a relatively high possibility that an erroneous measurement will be performed when a non-genuine sensor unit 4 is used.

Figure 7 is a flow chart showing an outline of another example of the operation (measurement control) when switching to the second mode. When switching to the second mode in S104 of Figure 4, the CPU 21 of the device body 2 can perform processing to allow measurement using a non-genuine sensor unit 4 with restrictions (S401). Then, the CPU 21 of the device body 2 can perform processing to display on the display unit 27 information indicating that the sensor unit 4 is non-genuine and that measurement using the sensor unit 4 is possible with restrictions (S402).

Examples of processes that allow measurement in S402 with restrictions include the following. For example, in processes that output measurement results, such as displaying the measurement results on the display unit 27, printing the measurement results using a printer provided in or connected to the device main body 2, displaying on the display means of an external device, or recording the measurement results in a storage medium provided in or connected to the device main body 2 or an external device, information indicating that the measurement results were obtained using a non-genuine sensor unit 4 can be displayed, printed, or recorded in association with the measurement results. In addition, when the specified measurement information cannot be read from the sensor memory 42, some functions can be disabled. Here, cases where the specified measurement information cannot be read from the sensor memory 42 include cases where the specified measurement information is not stored in the sensor memory 42 (including cases where the specified measurement information cannot be read because it is not stored in a specified description format), cases where the corresponding measurement information is stored but the use of the measurement information may be inappropriate, and the like. For example, in a configuration in which the sensor unit 4 includes a temperature sensor for temperature compensation such as a thermistor and a temperature sensor for temperature measurement, there may be cases in which the sensor memory 42 does not store characteristic data of the thermistor as predetermined measurement information, such as B constant, nominal resistance value, temperature table, etc. In addition, in consideration of the characteristics of the thermistor provided in a genuine sensor unit 4, there may be a relatively high possibility that the characteristic data of the thermistor stored in the sensor memory 42 of an inauthentic sensor unit 4 is inappropriate. In such cases, functions that use the detection results of the temperature sensor, such as the output of the temperature measurement value or the automatic temperature compensation (ATC) function, may be disabled.

As for the display in S402, for example, when the measured value is displayed with a notice that the sensor unit 4 is not genuine as described above, a warning message such as "The sensor is not genuine. The measurement accuracy may decrease. The measured value will record that a non-genuine sensor was used" can be displayed as shown in FIG. 11(b). When the function using the detection result of the temperature sensor provided in the sensor unit 4 is disabled as described above, a warning message such as "The sensor is not genuine. The automatic temperature compensation (ATC) function is disabled. Temperature must be measured separately and temperature compensation must be performed" can be displayed as shown in FIG. 11(c). In this way, by allowing measurements using a non-genuine sensor unit 4 with restrictions, a user who has obtained a non-genuine sensor unit 4 can perform measurements within the range of accuracy that he or she requires after recognizing that the sensor unit 4 is not genuine.

Figure 8 is a flowchart showing an outline of yet another example of the operation (measurement control) when switching to the second mode. When switching to the second mode in S104 of Figure 4, the CPU 21 of the device body 2 can prompt the user to input the predetermined measurement information that cannot be read from the sensor memory 42 from the operation unit 26 as a separate input means by displaying it on the display unit 27 (S501). Next, the CPU 21 of the device body 2 determines whether the predetermined measurement information has been input (S502). Then, if the CPU 21 of the device body 2 determines that the predetermined measurement information has been input in S502, it instructs the CPU 56 of the measurement unit 5 to store the input predetermined measurement information in the measurement unit memory 58 (or the storage unit of the CPU 56 of the measurement unit 5) (S503). After that, the CPU 21 of the device body 2 enables measurement after displaying a warning message similar to the example described in Figure 7 (S504). At this time, the CPU 21 of the device body 2 may allow measurement using the non-genuine sensor unit 4 with virtually no restrictions (substantially all functions can be used), or may allow it with restrictions (for example, disabling the temperature measurement and automatic temperature compensation functions) as in the example described in FIG. 7. On the other hand, if the CPU 21 of the device body 2 determines in S502 that the specified measurement information has not been input (for example, if a specified time has passed without input or if an instruction to cancel the input operation has been input), it prohibits measurement using the non-genuine sensor unit 4 (S505) and displays an error message on the display unit 27 (S506), as in S301 and S302 of FIG. 6.

Examples of the predetermined measurement information prompted to be input in S501 include the cell constant when the sensor unit 4 is a sensor unit 4B for measuring electrical conductivity, and the ion valence when the sensor unit 4 is a sensor unit 4 for measuring ions. In this case, in S501, as shown in FIG. 12(a), a display prompting the input of the cell constant and the ion valence can be displayed on the display unit 27. The same applies to sensors having other electrode coefficients (e.g., a residual chlorine electrode).

9 is a flow chart showing an outline of yet another example of the operation (measurement control) when switching to the second mode. When switching to the second mode in S104 of FIG. 4, the CPU 21 of the device body 2 can prompt the user to input a passcode as pass information from the operation unit 26 as an input means by displaying on the display unit 27 as shown in FIG. 12(b) (S601). The passcode can be, for example, character string information such as "345678" or "c2d3". Next, the CPU 21 of the device body 2 judges whether the passcode has been input (S602). If the CPU 21 of the device body 2 judges in S602 that the passcode has been input, it judges whether the input passcode is a predetermined passcode (S603). For example, the predetermined passcode can be provided to the user in advance via an instruction manual provided to the authorized user of the device body 2 or an account information display provided to the authorized user via a computer network such as the Internet. Also, a passcode for verification corresponding to the predetermined passcode can be stored in the main body memory 28. The CPU 21 of the device body 2 judges that the input passcode is a predetermined passcode when the input passcode matches the passcode for verification stored in the main memory 28, and judges that the input passcode is not the predetermined passcode when the input passcode does not match. If the CPU 21 of the device body 2 judges that the input passcode is the predetermined passcode in S603, it displays a warning message similar to the example described in FIG. 7, and then enables measurement (S604). At this time, the CPU 21 of the device body 2 may enable measurement using the non-genuine sensor unit 4 substantially without restrictions (substantially all functions can be used), or may enable measurement with restrictions (for example, the temperature measurement and automatic temperature compensation functions are disabled) similar to the example described in FIG. 7. Also, if the predetermined measurement information can be read from the sensor memory 42, the predetermined measurement information can be obtained from the sensor memory 42 similar to the case of using the genuine sensor unit 4 described in FIG. 5. Also, at this time, if the specified measurement information cannot be read from the sensor memory 42, the user can input the specified measurement information separately, as in the example described in FIG. 8.

On the other hand, if the CPU 21 of the device body 2 determines in S603 that the passcode is not the specified one, it can return to the process of S602 and prompt the user to enter the passcode again. If the CPU 21 of the device body 2 determines in S602 that the passcode has not been entered (for example, if a specified time has passed without an entry being made or if an instruction to cancel the input operation has been entered), it prohibits measurement using an unauthorized sensor unit 4 (S605) and displays an error on the display unit 27 (S606), similar to S301 and S302 in FIG. 6. In other words, the CPU 21 of the device body 2 can execute a pass process that determines whether or not a proper passcode has been acquired from an input means other than the sensor unit 4, and enables measurement if the passcode has been acquired, and prohibits measurement if the passcode has not been acquired.

In the above example, the means for notifying information required when the sensor unit 4 is not genuine (notification means for errors, warnings, etc.) is not limited to displaying a message on the display unit 27. Instead of or in addition to displaying a message on the display unit 27, the following notification means can be used. For example, a sound (alarm) such as a voice message, a beep, or a buzzer can be emitted from a speaker or the like serving as sound generation means provided on the device body 2. Also, for example, a light such as a warning light serving as light generation means provided on the device body 2 can be turned on or blinked. Also, for example, the above-mentioned notification can be made by the display means, sound generation means, or light generation means of an external device connected to the device body 2 in a communicable manner.

In the above example, the means for inputting information required when the sensor unit 4 is not genuine (input means for specific measurement information, passcode, etc.) is not limited to input from the operation unit 26. Instead of or in addition to input from the operation unit 26, the following input means can be used. For example, input can be made from an external device communicatively connected to the device main body 2. In this case, the user may manually input information from the operation unit of the external device, or the information may be input by a program installed in the external device that has a function for inputting information to the device main body 2, such as a data collection program provided to a genuine user of the device main body 2.

The measuring device 1 may be capable of selecting and executing multiple types of operations from among the above examples when a non-genuine sensor unit 4 is connected, for example, depending on the type of sensor unit 4.

Although not shown in the above examples, in a measurement device 1 capable of measuring multiple different measurement items as in this embodiment, when a non-genuine sensor unit 4 is connected and measurement is enabled, the display on the display unit 27 and the functions of the operation unit 26 may be manually switched by the user's operation on the operation unit 26.

As described above, according to this embodiment, it is possible to recognize that a user is using a non-genuine sensor, and to fully anticipate the results of using a non-genuine sensor, without simply prohibiting the use of non-genuine sensors across the board, and then to enable the use of non-genuine sensors. This makes it possible to prevent unexpected measurement results caused by the user carelessly using a non-genuine sensor, and to safely perform measurements with the desired accuracy.

[Example 2]
Next, another embodiment of the present invention will be described. In the measurement device of this embodiment, elements having the same or corresponding functions or configurations as those of the measurement device of the first embodiment will be given the same reference numerals as in the first embodiment, and detailed description will be omitted. In this embodiment, other examples of identification information and path information will mainly be described.

1. Identification information The identification information can be changed according to a predetermined rule. For example, the identification means is configured to include a memory, a CPU, and a battery. The CPU changes and updates the identification information according to a predetermined rule and stores it in the memory. As an example, the identification information is an identification code including a variable that increases by a predetermined value N at a predetermined timing as a predetermined rule. Furthermore, the identification code for collation stored in the main body memory 28 is an identification code including a variable that increases by a predetermined value N at a predetermined timing according to a corresponding rule by the CPU 21 of the device main body 2. The predetermined timing can be, for example, every month or every day using a clock function provided in the CPU. This identification code may be entirely composed of variables, or may include an unchanging part consisting of information such as the type of the sensor unit 4 (measurement item, model, etc.) and a variable part. Furthermore, the variable of this identification code can be set to return to an initial value when it reaches a predetermined upper limit value (limit value). Furthermore, the identification code and the predetermined rule are not made public. Then, the CPU 21 of the device main body 2 can determine that the sensor unit 4 is genuine if the identification code stored in the sensor memory 42 matches the identification code for verification stored in the main body memory 28, depending on the variables at the time of determining whether the sensor unit 4 is genuine or not. This reduces the possibility that the identification information will be counterfeited, and can increase the accuracy of determining whether the sensor unit 4 is genuine based on the identification information (strengthen security).

In addition, the identification information can be more than just an identification code; multiple factors can be checked to determine whether the product is genuine. Some examples are described below.

For example, the identification information may be an identification code including information on the type of sensor unit 4 (measurement items, model, etc.) and an individual code unique to each individual sensor unit 4 (such as a manufacturing number consisting of a serial number, etc.). In this case, for example, the sensor memory 42 stores the identification code and the individual code as the identification information. Also, for example, the main body memory 28 stores the identification code and information on the individual code assigned to each sensor unit 4 (such as information on the range of individual codes, such as 001A0001 to 999Z9999) as information for comparison. Then, the CPU 21 of the device main body 2 can determine that the sensor unit 4 is genuine when both the identification code and the individual code stored in the sensor memory 42 match the information for comparison stored in the main body memory 28.

For example, the sensor memory 42 can store manufacturing time information indicating the time when the sensor unit 4 was manufactured and connection time information indicating the time when the sensor unit 4 was first connected to the measuring device 1. That is, after the sensor unit 4 is manufactured, it may be connected to the measuring device 1 within a certain period according to the manufacturer's procedure and inspected. The measuring device 1 used for this inspection may be substantially the same as the measuring device 1 provided to the user, or may correspond to the measuring device 1 provided to the user, which has at least the function of performing a predetermined inspection (which may be calibration) of the sensor unit 4. The manufacturing time information can be information on the manufacturing date and the manufacturing month. The connection time information can be information on the connection (inspection) date and the connection (inspection) month. In general, the time indicated by the manufacturing time information and the time indicated by the connection time information for a certain sensor unit 4 are relatively close to each other within a certain range. Therefore, the comparison result between the manufacturing time information and the connection time information can be used to determine whether the product is genuine. In this case, for example, the sensor memory 42 stores an identification code, an individual code, manufacturing time information, and connection time information. Also, for example, the main body memory 28 stores, as information for comparison, an identification code, an individual code, and information on a predetermined relationship between the time indicated by the manufacturing time information and the time indicated by the connection time information (such as a threshold value indicating the period between the two periods). Then, the CPU 21 of the device main body 2 can determine that the sensor unit 4 is genuine when both the identification code and the individual code stored in the sensor memory 42 match the information for comparison stored in the main body memory 28, and the relationship between the time indicated by the manufacturing time information stored in the sensor memory 42 and the time indicated by the connection time information satisfies the predetermined relationship stored in the main body memory 28 (for example, the period between the two periods is equal to or less than a threshold). Note that the authenticity of the sensor unit 4 may be determined based only on the identification code and the relationship between the above-mentioned two periods. Also, the manufacturing time information may constitute a part of the individual code.

In addition, there are sensor units 4 that require inspection under the Measurement Act when used for trade certification, such as a sensor unit 4 equipped with a pH electrode. In the case of such a sensor unit 4, information on approval under the Measurement Act (such as information on the electrode certification number under the Measurement Act) is stored in the sensor memory 42, and this can be used to determine whether the product is genuine. In this case, for example, the sensor memory 42 stores an identification code, an individual code, manufacturing time information, connection time information, and information on approval under the Measurement Act. In addition, the main body memory 28 stores, as information for comparison, an identification code, an individual code, information on a predetermined relationship between the time indicated by the manufacturing time information and the time indicated by the connection time information, and information on approval under the Measurement Act. The CPU 21 of the device main body 2 can determine that the sensor unit 4 is genuine if the relationship between the identification code, individual code, and the time indicated by the manufacturing time information stored in the sensor memory 42 and the time indicated by the connection time information each satisfy the predetermined conditions stored in the main body memory 28, and the information regarding approval based on the Measurement Act stored in the sensor memory 42 matches the information for verification stored in the main body memory 28. Note that the information regarding approval based on the Measurement Act can be used in combination with only the identification code, or in combination with only the identification code and individual code.

In this way, by performing double, triple, or quadruple checks using an individual code, information on the relationship between manufacturing date information and connection date information, or information on approval based on the Measurement Act in addition to the identification code, it is possible to increase the accuracy of identifying genuine products (strengthen security).

2. Password information In the first embodiment, an example was described in which, when an unauthorized sensor unit 4 is connected to the measurement device 1, measurement using the sensor unit 4 is possible on the condition that password information is input. The password information is stored in the main body memory 28 while an unauthorized sensor unit 4 is connected to the measurement device 1, and measurement using the sensor unit 4 can be possible without re-input. Alternatively, even if an unauthorized sensor unit 4 is continuously connected to the measurement device 1, re-input of password information can be required. For example, re-input of password information can be required every predetermined period (for example, once a year, once a month, etc.) in the same manner as described in the first embodiment. Also, re-input of password information can be required every time the power of the measurement device 1 is turned on in the same manner as described in the first embodiment. By requiring re-input of password information in this manner, for example, it is possible to reduce the possibility that a plurality of different operators will mistakenly recognize that the sensor unit 4 connected to the measurement device 1 is authorized, and to perform measurements with the desired accuracy more safely.

[Example 3]
Next, another embodiment of the present invention will be described. In the measurement device of this embodiment, elements having the same or corresponding functions or configurations as those of the measurement device of the first embodiment will be given the same reference numerals as in the first embodiment, and detailed description will be omitted. In this embodiment, another example of the sensor unit will be mainly described.

(I) In the above embodiment, the sensor unit 4 of the probe 3 for measuring potential difference has been described as having a pH electrode, but it may have an electrode selected from potential difference measurement electrodes including at least one of a pH electrode, an oxidation-reduction potential difference measurement electrode (ORP electrode), and an ion electrode. Examples of ion electrodes other than a pH electrode (ion electrodes) include a sodium ion electrode, a chloride ion electrode, a bromide ion electrode, an iodide ion electrode, a cyanide ion electrode, a cadmium ion electrode, a copper ion electrode, a silver ion electrode, a sulfide ion electrode, a fluoride ion electrode, a potassium ion electrode, a calcium ion electrode, a nitrate ion electrode, an ammonia electrode, and a carbon dioxide electrode. Other available ion electrodes may also be used.

(II) In the above embodiment, the sensor unit 4 of the redox current measuring probe 3 has been described as having a dissolved oxygen electrode, but it may have an electrode selected from redox current measuring electrodes including at least one of a dissolved oxygen electrode, a residual chlorine electrode, a dissolved ozone electrode, a chlorine dioxide electrode, a chlorite ion electrode, a hydrogen peroxide electrode, and a dissolved hydrogen electrode. These redox current measuring electrodes are, for example, diaphragm-type or exposed-type polarographic or galvanic redox current measuring electrodes. Other available redox current measuring electrodes may also be used.

(III) The measuring device 1 may be capable of being used by connecting a probe 3 equipped with an optical sensor as a sensor unit 4 instead of or in addition to at least one of the probes 3 for measuring potential difference, the probe 3 for measuring electrical conductivity, and the probe 3 for measuring redox current. Examples of optical sensors include a turbidity sensor, an optical dissolved oxygen sensor, an absorbance sensor, and a fluorescence sensor. Other available optical sensors may also be used.

An example of a turbidity sensor is a 90° scattered light measurement type. The turbidity sensor has, for example, a light-projecting section and a light-receiving section in the sensor unit 4, introduces light from the light-projecting section into the sample liquid introduced into the sample liquid introduction section provided in the sensor unit 4, and outputs a signal according to the amount of light scattered by the sample liquid received by the light-receiving section. The measurement circuit 51 for turbidity measurement provided in the measurement unit 5 detects a signal emitted by the turbidity sensor according to the amount of scattered light received in the 90° direction when the turbidity sensor introduces light into the sample liquid as described above. Other types can also be used.

As an absorbance sensor, for example, the sensor unit 4 has a light-projecting section, a light-receiving section, and a sample liquid introduction section, and the light-projecting section projects light into the sample liquid in the sample liquid introduction section, and the light-receiving section detects the light that has passed through the sample liquid and outputs a signal corresponding to the amount of light. The measurement circuit 51 for measuring absorbance provided in the measurement unit 5 irradiates the sample liquid with light from the light-projecting section, and detects the signal emitted by the light-receiving section when it receives the light that has passed through the sample liquid as described above.

The fluorescent sensor has, for example, an excitation light projector as an excitation stimulus generator in the sensor unit 4, and a light receiver, and irradiates the sample liquid introduced into the sample liquid introduction section provided in the sensor unit 4 with excitation light from the excitation light projector, and outputs a signal corresponding to the amount of fluorescence emitted by the sample liquid and received by the light receiver. The measurement circuit 51 for fluorescence measurement provided in the measurement unit 5 irradiates the sample liquid with excitation light from the excitation light projector, and detects a signal emitted by the fluorescent sensor according to the amount of fluorescence emitted by the sample liquid and received by the fluorescent sensor as described above. Note that optical dissolved oxygen sensors are known that detect a shortening of the fluorescence duration or a decrease in the intensity of fluorescence caused by the fluorescence of a fluorescent dye being hindered by dissolved oxygen. The configuration of this optical dissolved oxygen sensor is roughly the same as the above-mentioned fluorescent sensor, but instead of the sample liquid introduction section, it has an oxygen permeable membrane and a fluorescent dye membrane to which a fluorescent dye that emits fluorescence in response to excitation light of a specific wavelength is fixed, and is configured to irradiate the fluorescent dye membrane with excitation light to generate fluorescence and detect the duration and intensity of the fluorescence.

(IV) The measuring device 1 may be capable of being used by connecting a probe 3 equipped with a pressure sensor (pressure electrode) as a sensor unit 4 in place of or in addition to at least one of the probes 3 for measuring potential difference, the probe 3 for measuring electrical conductivity, the probe 3 for measuring redox current, and the probe 3 for an optical measurement object. The pressure sensor is used for measuring atmospheric pressure, for compensating for the atmospheric pressure of a diaphragm-type electrode together with the electrode, for measuring water depth in a dam, etc.

Examples of pressure sensors include diaphragm-type pressure sensors and semiconductor pressure sensors that are well known to those skilled in the art. Diaphragm-type pressure sensors have a diaphragm in the probe body as a pressure-sensitive element, and convert the displacement of the diaphragm into an electrical quantity and output it. For example, a method is known in which the diaphragm is used as a grounded movable electrode, insulated fixed electrodes are placed on both sides of the diaphragm, and the displacement of the diaphragm is converted into a ratio of the voltages across a capacitor using a constant frequency power source, thereby outputting the displacement of the diaphragm as an electrical signal in a capacitive manner. Also, a semiconductor pressure sensor is known to have a pressure-sensitive chip built in, such as a piezoresistance element formed on a Si diaphragm and bridge-coupled in a space filled with a constant pressure gas such as helium. When these pressure sensors can be connected, the measurement circuit 51 for pressure measurement provided in the measurement unit 5 applies a voltage to the pressure-sensitive element to detect the ratio of the voltages across the capacitor or the change in electrical resistance. Other types of pressure sensors may also be used.

(V) The measuring device 1 can also be used by connecting a single probe 3 equipped with a temperature sensor as the sensor unit 4.

[others]
Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments.

For example, in the above embodiment, the analog signal obtained from the sensor unit is converted to a digital signal by the measurement circuit of the measurement unit, and the CPU of the measurement unit calculates and determines the measurement value based on the digital signal and measurement information such as calibration data and correction values. Alternatively, the CPU of the device body may calculate and determine the measurement value based on the digital signal obtained from the measurement circuit of the measurement unit and the measurement information. In this case, if the measurement information is stored in the sensor memory, the CPU of the device body can read the measurement information from the sensor memory and store it in the main body memory (or the memory unit of the CPU of the device body) for use. Furthermore, the CPU of the sensor unit or the CPU of the device body may be given the role of performing calculations such as temperature compensation calculations related to measurements and unit conversions associated with changes in unit settings.

In the above embodiment, the measuring device is configured such that the sensor unit is detachable from the measurement unit, but an integrated sensor having the functions of the sensor unit and the measurement unit in the above embodiment may be detachable from the device body. In this case, the integrated sensor constitutes a sensor that is detachable from the measuring device. In this case, for example, the sensor memory may be provided on a printed circuit board of the integrated sensor, and other elements such as a measurement circuit may be provided on the same printed circuit board. Note that in genuine products, the sensor unit and the measurement unit are detachable as in the above embodiment, but in non-genuine products, it is possible that the part corresponding to the sensor unit and the part corresponding to the measurement unit in the above embodiment are integrated.

The measurement device is not limited to a configuration in which a measurement circuit is provided in a probe (for example, the measurement unit in the above-mentioned embodiment, or the above-mentioned integrated sensor) that is detachable from the device body, and a digital signal related to the measurement result is transmitted between the probe and the device body. The measurement device may be configured such that a measurement circuit is provided in the device body, and an analog signal related to the measurement result (electrode detection signal) is transmitted between the sensor that is detachable from the device body and the device body. In this case, too, by providing an identification means, for example having a memory, in the sensor (including a cable or connector), and providing a recognition means in the device body that reads and recognizes the identification information attached to this identification means, it is possible to obtain the same effect as in the above-mentioned embodiment by the same action as in the above-mentioned embodiment.

Reference Signs List 1 Measuring device 2 Device body 3 Probe 3A pH measurement probe (first probe)
3B Probe for measuring electrical conductivity (second probe)
3C Probe for measuring dissolved oxygen (second probe)
4. Sensor unit (sensor that can be attached to the measuring device)
5 Measurement unit 21 CPU of device main body
22 Main body side connector 42 Sensor memory (identification means)
51 Measuring circuit 52 Probe side connector

Claims (16)

In a measuring device in which a sensor according to the object to be measured can be attached and detached,
A control means for controlling the measurement using the sensor,
The control means
an identification process for determining whether the connected sensor is genuine or not based on acquisition of identification information from the sensor when the sensor is connected;
a switching process for switching the control between a first mode corresponding to a case where the sensor is genuine and a second mode corresponding to a case where the sensor is not genuine according to a result of the identification process;
It is possible to execute
The measurement device is characterized in that, when the control means switches the control to the second mode, it executes path processing to determine whether or not specified path information has been acquired from an input means other than the sensor, and, depending on the result of the path processing, enables measurement if the specified path information has been acquired, and prohibits measurement if the specified path information has not been acquired . In a measuring device in which a sensor according to the object to be measured can be attached and detached,
A control means for controlling the measurement using the sensor,
The control means
an identification process for determining whether the connected sensor is genuine or not based on acquisition of identification information from the sensor when the sensor is connected;
a switching process for switching the control between a first mode corresponding to a case where the sensor is genuine and a second mode corresponding to a case where the sensor is not genuine according to a result of the identification process;
It is possible to execute
A measuring device characterized in that, when the control means switches the control to the second mode, it executes a process to acquire, from an input means separate from the sensor, specified information regarding measurement that can be acquired from the sensor in the first mode. 3. The measuring device according to claim 2 , wherein the predetermined information is information necessary for converting an output of the sensor into a measured value. 4. The measuring device according to claim 3, wherein the predetermined information includes at least one of information regarding a cell constant when the sensor is an electrical conductivity cell, information regarding an ion valence when the sensor is an ion electrode, information regarding an electrode coefficient when the sensor is a residual chlorine electrode, and information regarding characteristics of a temperature detection element provided in the sensor . In a measuring device in which a sensor according to the object to be measured can be attached and detached,
A control means for controlling the measurement using the sensor,
The control means
an identification process for determining whether the connected sensor is genuine or not based on acquisition of identification information from the sensor when the sensor is connected;
a switching process for switching the control between a first mode corresponding to a case where the sensor is genuine and a second mode corresponding to a case where the sensor is not genuine according to a result of the identification process;
It is possible to execute
A measuring device characterized in that, in the second mode, the control means does not execute processing related to a function that uses the detection results of a temperature detection element provided in the sensor, which is a portion of the functions that can be executed in the first mode. 6. The measuring device according to claim 1, wherein the control means acquires identification information attached to an identification means provided in the sensor through communication with the sensor. The measuring device according to claim 6, characterized in that the identification means is configured to have a storage medium, the identification information includes information of a specific identification code predetermined according to the type of the sensor, and the control means determines that the sensor is genuine when the identification code satisfies predetermined conditions. The measuring device according to claim 7, characterized in that the identification information further includes information of an individual code unique to each of the sensors, and the control means further determines that the sensor is genuine if the individual code satisfies a predetermined condition. The measuring device described in claim 7 or 8, characterized in that the storage medium stores manufacturing date information indicating the date when the sensor was manufactured and connection date information indicating the date when the sensor was first connected to the measuring device, and the control means further determines that the sensor is genuine when a relationship between the manufacturing date information and the connection date information satisfies a predetermined condition. The measuring device according to any one of claims 7 to 9, characterized in that the storage medium stores information regarding approval based on the Measurement Act, and the control means further determines that the sensor is genuine if the information regarding approval based on the Measurement Act satisfies predetermined conditions. In a measuring device in which a sensor according to the object to be measured can be attached and detached,
A control means for controlling the measurement using the sensor,
The control means
an identification process for determining whether the connected sensor is genuine or not based on acquisition of identification information from the sensor when the sensor is connected;
a switching process for switching the control between a first mode corresponding to a case where the sensor is genuine and a second mode corresponding to a case where the sensor is not genuine according to a result of the identification process;
It is possible to execute
The control means acquires identification information attached to an identification means provided in the sensor through communication with the sensor,
the identification means is configured to have a storage medium, the identification information includes a specific identification code information predetermined according to the type of the sensor, and the storage medium stores manufacturing time information indicating the time when the sensor was manufactured and connection time information indicating the time when the sensor was first connected to the measuring device,
The measuring device is characterized in that the control means determines that the sensor is genuine when the identification code satisfies predetermined conditions and, further, when the relationship between the manufacturing date information and the connection date information satisfies predetermined conditions. The measuring device according to claim 11, characterized in that the identification information further includes information of an individual code unique to each of the sensors, and the control means further determines that the sensor is genuine if the individual code satisfies a predetermined condition. The measuring device according to claim 11 or 12, characterized in that the storage medium stores information regarding approval based on the Measurement Act, and the control means further determines that the sensor is genuine if the information regarding approval based on the Measurement Act satisfies predetermined conditions. 14. The measuring apparatus according to claim 1, wherein the control means executes, in the second mode, a predetermined process that is not executed in the first mode. 15. The measuring device according to claim 14 , wherein the predetermined process is a process of outputting information indicating that the sensor is not a genuine product. 16. The measuring device according to claim 1, further comprising: a sensor unit including the sensor; a measurement unit to which the sensor unit is detachably connected and which includes a measurement circuit for converting an analog signal obtained from the sensor into a digital signal indicating a measurement value; and a device main body to which the measurement unit is detachably connected and which includes a display unit for displaying the measurement value, wherein the control means is provided in at least one of the measurement unit and the device main body.

Images