JP7160673B2 - Flowmeter - Google Patents

Description

The present invention relates to flow meters.

Patent Literature 1 discloses a clamp-on type fluid flow meter retrofitted to piping. This fluid flow meter is equipped with a display unit composed of a 3-digit 7-segment LED, and the display unit has a function to switch the numerical display of instantaneous flow rate, threshold value, and integrated flow rate at predetermined time intervals. .

Patent Literature 2 discloses the use of a differential pressure sensor to measure the leak flow rate of air from a container.

Patent Document 3 discloses an ultrasonic vortex flowmeter with a display. This fluid flow meter has a main body and a display section separated from each other, and a display device is arranged in the display section. This display device has the function of switching the numerical display of the instantaneous flow rate generated by the main body, the integrated flow rate value, and the like. Here, the integrated value is a flow rate integrated from a predetermined time point.

Patent Literature 4 discloses a thermal gas flow meter. This flow meter has a head section and an amplifier section, which are separate. The amplifier section contains a microprocessor and the head section does not have a microprocessor. The head section has a display section, and a pattern display corresponding to the detected flow rate is performed on this display section.

Patent Document 5 discloses a clamp-on type ultrasonic flowmeter. This flow meter has a display for numerically displaying the instantaneous flow rate and the threshold value. This flow meter is preferably applied to liquids, and is intended to recognize changes in flow rate over time in order to manage the operational status of equipment in a factory. To this end, the flow meter of US Pat. No. 5,900,000 is designed to output an on/off signal based on the flow rate of fluid flowing through the pipe.

JP-A-2002-267509 JP 2004-163378 A JP 2004-347352 A Japanese Patent Application Laid-Open No. 2005-315712 JP 2016-219114 A

In factories, there are many devices that use compressed air as a drive source. Compressed air is supplied from the compressor to the equipment through piping laid in the factory, and at that time, electric energy corresponding to the generated compressed air is applied to the compressor. In order to appropriately manage the energy used in factories, the management of the compressed air used is also one of the important factors.

In order to quantitatively manage the amount of compressed air that is used, sensing devices, etc. are placed in appropriate locations on the pipes laid in the factory, and the sensing devices, etc. It is necessary to build a system that aggregates sensing data from sensing devices, etc.

However, building a system that quantitatively manages the amount of compressed air used is cumbersome, and the sensing data that is acquired is constantly updated according to the operating status of equipment that uses compressed air as a drive source. It changes, and as it is, it is not suitable for management.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flowmeter which has a display section and which makes it easy to grasp the leak situation from the information displayed on the display section.

The above technical problem, according to the present invention,
a flow rate measuring means for measuring the flow rate of the fluid in the pipe;
a calculation means for determining a leak amount based on the flow rate measured by the flow rate measurement means under certain conditions and calculating an integrated leak amount for each predetermined date and time segment;
a display screen generating means for generating a display screen for graphically displaying an integrated leak amount corresponding to each date/time segment in a display range composed of a plurality of date/time segments;
and a display for displaying the graph display screen generated by the display screen generation means.

A typical example of a constant condition for determining the amount of leakage is late at night or a holiday when equipment in a factory is out of service. The gas flowmeter according to the present invention does not display the instantaneous flow rate, but graphically displays the integrated leak amount corresponding to each date/time segment in a display range composed of a plurality of date/time segments. By looking at , it is possible to sensuously grasp the change in the leak amount in time series.

The advantages and further objects of the present invention will become apparent from the detailed description of preferred embodiments of the present invention below. As a typical example, a gas flow meter in which the fluid to be measured is gas will be described as an example, but the present invention is not limited to gas, but can be suitably applied to flow meters for liquids. .

1 is a perspective view showing a state in which a clamp-on type ultrasonic gas flowmeter to which the present invention is applied is attached to a pipe; FIG. FIG. 2 is a cross-sectional view of a sensor body of the gas flow meter illustrated in FIG. 1; FIG. 10 is a perspective view for explaining a usage pattern in which the display section is used with the display section separated from the sensor main body; FIG. 4 is a diagram for explaining the internal structure of the sensor main body and the display unit. 3 is a functional block diagram of a display unit; FIG. FIG. 4 is a diagram for explaining display data collection in a memory; FIG. 10 is a diagram for exemplifying difference calculation and overflow processing; FIG. 4 is a diagram for explaining an overview of display using a color liquid crystal that is a display device of the display section; FIG. 4 is a diagram for explaining an example of items displayed in a main display area of a color liquid crystal; FIG. 10 is a diagram for explaining a graph display of history; FIG. 10 is a diagram for explaining graph display of each time segment in the case of a display range including the present; FIG. 10 is a diagram for explaining a header display area displayed above the color liquid crystal; FIG. 10 is a diagram for explaining a footer display area displayed below the color liquid crystal; It is a figure which shows the display screen which displays an instantaneous flow volume. FIG. 10 is a diagram showing a display screen that simultaneously displays a usage amount graph and numerical values; It is a figure which shows the display screen which displays a usage-amount. FIG. 10 is a diagram showing a display screen that simultaneously displays a usage amount comparison graph and a comparison rate; FIG. 10 is a diagram showing a display screen that displays usage amounts in the positive and negative directions in bar graphs and numerical values; FIG. 4 is a diagram for explaining display switching; FIG. FIG. 10 is a diagram showing a display screen that displays the leak amount in graphs and numerical values; FIG. 10 is a diagram showing a display screen that displays the usage amount and the leak amount at the same time; FIG. 10 is a diagram showing a display screen displaying a leak rate; 4 is a time chart showing a process of determining a reference leak amount based on a measured flow rate and obtaining a leak amount including during operation of the facility based on the standard leak amount. FIG. 4 is a conceptual diagram of processing in a leak amount determination mode for determining a reference leak amount; 4 is a flowchart for explaining a procedure for obtaining a reference leak amount;

An embodiment of the invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a state in which a clamp-on type ultrasonic gas flowmeter to which the present invention is applied is attached to a pipe, and FIG. 2 is a cross-sectional view of the sensor main body of the gas flowmeter shown in FIG. be. FIG. 3 is a perspective view for explaining a usage pattern in which the display section is used with the display section separated from the sensor main body.

The clamp-on type ultrasonic gas flowmeter Fm of the embodiment is designed to be suitably applied to the flow rate measurement of compressed air and nitrogen gas. Taking compressed air as an example, in a factory, a gas flow meter is attached to a pipe P that supplies air from a tank that stores air compressed by a compressor to each operating device that uses compressed air as an operating source. Fm is retrofitted.

The gas flow meter Fm has a sensor main body 2 installed in the pipe P and a display section 4 , and the display section 4 has a housing separate from the sensor main body 2 . That is, the gas flowmeter Fm is a separate type, and the sensor main body 2 and the display section 4 are separate structures. The display unit 4 is detachable from the sensor body 2 . Of course, the gas flow meter Fm may be of an integrated type in which the sensor main body 2 and the display section 4 are configured in one housing, for example.

The sensor main body 2 has a function of measuring the flow rate of the gas flowing through the pipe P, and as shown in FIG. there is That is, the first and second ultrasonic elements 6 and 8 are fixedly arranged inside a common main body housing 10 . The first and second ultrasonic elements 6, 8 are typically composed of piezoelectric elements.

Referring to FIG. 2, clamp-on type ultrasonic gas flow meter Fm has first and second ultrasonic elements 6 and 8 built in sensor main body 2 arranged on the generatrix of pipe P and along the axis of pipe P. Spaced apart in the direction of Ax. That is, the sensor main body 2 is a so-called V-arrangement type or reflective arrangement clamp-on type flowmeter. In the figure, reference symbol Us schematically represents the path of ultrasonic signals transmitted and received between the first and second ultrasonic elements 6 and 8 . As illustrated, the sensor main body 2 may emit ultrasonic waves across the pipe P, but is not limited to this. In the pipe wall of the pipe P, preferably, a natural vibration mode of the pipe wall such as Lamb wave or plate wave may be generated. Of course, in this case, the illustrated path Us should be understood to be schematic.

As a modification, the first and second ultrasonic elements 6 and 8 included in the sensor main body 2 may be arranged to face each other with the pipe P interposed therebetween. Specifically, the first ultrasonic element 6 is arranged on the first generatrix of the pipe P, and the second ultrasonic element 8 is arranged on the second generatrix diametrically opposed to the first generatrix, that is, the so-called Z arrangement. The present invention can also be preferably applied to a flow meter of the type.

The sensor body 2 includes a first wedge member 12 adjacent to the first ultrasonic element 6 and a second wedge member 14 adjacent to the second ultrasonic element 8 . The sensor body 2 also preferably includes first and second couplants 16, 18 adjacent the first and second wedge members 12, 14, respectively. Preferably, 18 constitutes a contact portion for the pipe P. Preferably, the first and second couplants 16, 18 are made of solid couplant in order to improve installation workability.

In the figure, reference numeral 20 designates a damping member. The damping member 20 is a sheet-shaped molded article having appropriate flexibility and preferably a predetermined thickness. It is preferable that the damping member 20 has viscoelasticity, and has adhesiveness and peelability to the metal pipe P. As shown in FIG. The damping member 20 can be easily deformed along the circumference of the pipe P by being traced by an operator's hand.

The damping member 20 is arranged adjacent to the sensor main body 2 and arranged so as to surround the pipe P while being in contact with the pipe P. As shown in FIG. The damping member 20 is fixed to the pipe P by a damping fixture 22 surrounding its outer periphery, and is pressed against the pipe P by the damping fixture 22 . That is, damping fixture 22 continues to maintain a pressure holding function for damping member 20 .

The first and second ultrasonic elements 6 and 8 built in the sensor main body 2 are fixedly set at a separation distance of, for example, 1 to 15 cm, preferably 2 to 6 cm, in the direction of the axis Ax of the pipe P. .

The damping member 20 and damping fixture 22 have hollow first and second damping windows 24, 26 which extend through the first and second couplants 16, 26; 18 are positioned.

1 and 3, the display unit 4 is connected to three waterproof cables 30, 32, 34. As shown in FIG. The first cable 30 includes a power cable that supplies power (for example, 24 V DC) to the display unit 4, a first output cable that supplies an analog signal corresponding to the instantaneous flow rate from the display unit 4 to the outside, and a pulse signal corresponding to the integrated flow rate. from the display unit 4 to the outside, and a third output cable to supply the ON/OFF signal, which is the comparison result with the threshold value, from the display unit 4 to the outside. The second cable 32 is an industrial transmission cable, and includes, for example, an EthernetIP communication cable, an EtherCAT (registered trademark) communication cable, a monitoring device, a communication cable with an external PC, and a cable that supplies the flow rate of the target gas from the display unit 4 to the outside. I'm in. The third cable 34 is a cable for connecting to the sensor main body 2 , and includes a cable for supplying power to the sensor main body 2 via the display unit 4 , a cable for providing setting information to the sensor main body 2 , and a cable for providing setting information to the sensor main body 2 . It includes a cable that supplies measured flow data from to the display 2 .

Continuing with FIGS. 1 and 3, the display unit 4 has a waterproof/dustproof case 36 that constitutes the housing of the display unit, and the waterproof/dustproof case 36 is separate from the sensor body 2 . The display unit 4 further includes a color liquid crystal 38 as a waterproof/dustproof display device, a waterproof menu button 40, and a waterproof/dustproof operation button 42. is provided with a selection function and a determination (SET) function used for selecting menus and icons displayed on the color liquid crystal 38 . The display unit 4 further has a USB port 44, and the USB port 44 can be waterproof and dustproof by closing a cover (not shown). The USB port 44 is used for connection with an external PC 46 (FIG. 4) for monitoring and/or setting.

The display unit 4 is positioned and fixed to the sensor main body 2 via a fixture F, as shown in FIG. The display portion 4 preferably has a locking hole H (FIG. 3) on its rear surface. The fixture F is detachable from the display unit 4 and detachable from the sensor main body 2 . When the display unit 4 is detached from the sensor main body 2, it is desirable to use the display unit 4 in a state where it is locked to a nail such as a post using the locking hole H. As shown in FIG.

FIG. 4 is a diagram for explaining the internal structures of the sensor main body 2 and the display section 4. As shown in FIG. Referring to FIG. 4, the sensor main body 2 includes a microprocessor 48 constituting a control unit for flow rate measurement, an ultrasonic element driving circuit 50 for controlling the irradiation of the first and second ultrasonic elements 6 and 8, This ultrasonic element driving circuit 50 is supplied with a drive t voltage for the ultrasonic element 6 (8) from a booster circuit 52 . The output of the ultrasonic element drive circuit 50 is sequentially supplied to the first and second ultrasonic elements 6 and 8 via the switching circuit 54 . The switching circuit 54 is switch-controlled in synchronization with the irradiation control of the first and second ultrasonic elements 6 and 8 . Through the switching circuit 54, the first ultrasonic element 4 functions as a transmitter and the second ultrasonic element 8 functions as a receiver in the forward transmission state. Similarly, in the backward transmission state, the second ultrasonic element 8 functions as a transmitter and the first ultrasonic element 6 functions as a receiver.

Outputs from the ultrasonic elements 6 and 8 are supplied to the receiving circuit 56 via the switching circuit 54 . The receiving circuit 56 amplifies the electrical signal, and the amplified analog signal is converted to a digital signal by the A/D converter 58 and input to the microprocessor 48 . The microprocessor 48 communicates with a memory 60 storing a prescribed program to execute prescribed processing.

In order to calculate the flow rate through the pipe P, the information required for this calculation is stored in the memory 60 . Typically, the microprocessor 48 aligns the forward-travel received waveform and the homeward-travel received waveform with the time at the point of emission of each of them as the origin, and generates the waveform shape while relatively displacing it in the time direction from this aligned state. perform matching. The amount of time shift that maximizes the degree of matching is determined as the propagation time difference, and the gas flow rate is calculated based on this propagation time difference.

The display unit 4 has a microprocessor 64 housed in a display housing separate from the sensor body 2, ie, a waterproof case 36 (FIG. 3). The microprocessor 64 constitutes a control section for controlling display, communicates with a memory 66 in which predetermined programs and applications are stored, and executes predetermined processing.

The display unit 4 further has a real-time clock (RTC) 68 that functions as a real-time clock, and this RTC 68 always operates with power supplied from the first cable 30 . As a modification, the backup battery 70 may be mounted on the display unit 4 so that the RTC 68 keeps keeping real time even when the power supply to the display unit 4 is stopped.

For example, a pressure sensor 72 installed in the pipe P is connected via the USB port 44 and the internal pressure value of the pipe P is input to the microprocessor 64 . The microprocessor 64 stores the flow rate data received from the sensor body 2 in the logging memory 74 . The logging memory 74 preferably has a capacity capable of recording the integrated flow rate and integrated leak amount for at least two years.

The integrated flow rate represents the total amount of gas that has passed through the pipe P from the first point of time to the second point of time. It represents the total amount of gas that has passed through the When based on the volumetric flow rate, the integrated flow rate is the volume of the gas that has passed through the pipe P, and its unit is, for example, cubic meters. Further, when the mass flow rate is used as a base, the integrated flow rate is the mass of the gas that has passed through the pipe P, and its unit is, for example, kilograms. Since the integrated flow rate represents the total amount of gas that has passed through the pipe P from the first time point to the second time point, the integrated flow rate is also referred to as the usage amount in this specification.

FIG. 5 is a functional block diagram of the display section 4. As shown in FIG. The display unit 4 has an instantaneous flow rate collection engine 80 that receives flow rate data supplied from the sensor body 2 . This instantaneous flow rate collection engine 80 acquires flow rate data from the sensor body 2 every 30 milliseconds, for example. This collection cycle time may be set arbitrarily.

The instantaneous flow rate collection engine 80 corrects the flow rate data based on information such as the pipe conditions such as the inner diameter of the pipe P, the environmental temperature, the pressure inside the pipe P, etc. supply to The instantaneous flow rate data temporarily held in the instantaneous flow rate buffer 82 is updated every 30 milliseconds, for example. This update cycle time may be arbitrarily settable.

Based on the instantaneous flow rate data held in the instantaneous flow rate buffer 82, the output processing unit 87 outputs an analog signal indicating the instantaneous flow rate to the outside via the second cable 32 (FIG. 3). In addition, the output processing unit 87, based on the result of comparison between the instantaneous flow rate data held in the instantaneous flow rate buffer 82 and a preset threshold value, outputs the on/off signal indicating the comparison result via the second cable 32. Outputs an off signal to the outside.

The instantaneous flow rate data is supplied from the instantaneous flow rate buffer 82 to the integrated flow rate processing engine 84, and the integrated flow rate processing engine 84 executes processing for calculating the integrated flow rate based on the instantaneous flow rate data, for example, every 1 millisecond. A trigger signal from the outside can be input to the integrated flow rate processing engine 84, and the integrated flow rate processing engine 84 calculates the integrated flow rate starting from the point of time when the trigger signal is input. That is, the integrated flow rate processing engine 84 resets the integrated flow rate to zero when the trigger signal is input, and executes integration processing based on the instantaneous flow rate data. This trigger signal corresponds to a reset signal. The integrated flow calculated by the integrated flow processing engine 84 is temporarily held as integrated flow data in an integrated flow buffer 86 . The integrated flow rate buffer 86 holds, as integrated flow rate data, the integrated flow rate starting from the time when the external trigger signal is input, and this integrated flow rate buffer 86 is updated, for example, every 1 millisecond. This update cycle time may be arbitrarily settable.

The integrated flow rate processing engine 84 accepts a reset instruction from the user via the operation units 40 and 42 in addition to a trigger signal from an external device. Integration processing based on flow data may be executed. The trigger input shown in FIG. 5 includes a reset instruction from the user and a trigger signal from an external device via the operation units 40 and 42 .

Based on the integrated flow rate data held in the integrated flow rate buffer 86, the output processing unit 87 outputs a pulse signal indicating the integrated flow rate to the outside via the second cable 32 (FIG. 3). In addition, the output processing unit 87, based on the result of comparison between the integrated flow rate data held in the integrated flow rate buffer 86 and a preset threshold value, outputs an on/off signal indicating the comparison result via the second cable 32. Outputs an off signal to the outside.

The total integrated flow rate buffer 88 temporarily holds the total integrated flow rate for calculating the integrated flow rate (usage amount) divided by time. The total integrated flow rate is a type of integrated flow rate (usage amount), and is an integrated flow rate (usage amount) that is not reset by a trigger input that is unrelated to time units. That is, the integrated flow rate processing engine 84 executes integration processing based on the instantaneous flow rate data without resetting the total integrated flow rate in the total integrated flow rate buffer 88 . The integrated flow rate processing engine 84 may reset the total integrated flow rate in the total integrated flow rate buffer 88 by a periodic trigger input related to time units, and perform the integration process based on the instantaneous flow rate data. This total integrated flow buffer 88 is updated, for example, every 1 millisecond. It is preferable that this update cycle time can be set arbitrarily.

The total integrated flow rate in the total integrated flow buffer 88 is stored in the logging memory 74 via the logging engine 90 . This memory is stored in areas of the logging memory 74 divided by, for example, one hour and in a state associated with the time from the RTC 68 .

As for compressed air leaks, the amount of leaks fluctuates under the influence of factors such as the operating conditions of equipment in the factory, the internal pressure of pipes, and the environmental temperature. The leak amount is defined, for example, by the flow rate measured late at night or on a holiday when the equipment in the factory is out of service, and the current leak amount is determined by taking into consideration parameters such as the internal pressure of the pipe and the environmental temperature. Regarding this leak amount, the leak amount is calculated by the leak amount processing engine 92 from the instantaneous flow rate buffer 82, and the leak amount obtained by the leak amount processing engine 92 is temporarily accumulated in the leak amount buffer 94, and then the leak integrated amount is processed. An integrated value of the leak amount is obtained by the engine 96 , and this integrated value is temporarily stored in the total integrated leak amount buffer 98 and then stored in the logging memory 74 via the logging engine 90 . The storage of the total leak integrated amount is stored in areas of the logging memory 74 divided by, for example, one hour and linked to the time from the RTC 68 .

The logging memory 74 adds a log every hour when the storage format is time-separated, that is, predetermined in units of one hour. The display processing engine 100 generates a display image of the usage amount for each day/time segment, the leak integrated amount for each day/time segment, etc., based on the total integrated flow rate and the total leak integrated amount stored in the logging memory 74 . A display image generated by the display processing engine 100 is displayed on the liquid crystal monitor 38, which is a display device. The display of the liquid crystal monitor 38 is updated, for example, every 200 milliseconds. It is preferable that this display update cycle time can be set arbitrarily.

Display data collection in the logging memory 74 will be described with reference to FIG. , . . . , M(n), and the total integrated flow rate and the total leak integrated amount are stored in sequence in each storage area M(n). The total integrated flow rate and the total leak integrated amount are stored in the corresponding storage areas M(n) in a state in which the year/month/date data 102 of the memory head address and the time information (year/month/date information) of the RTC 68 are linked. . Each storage area M(n) is associated with an address offset amount and a time offset amount from the leading address. As a result, the memory address is uniquely determined for the desired time, so there is an advantage that the time search is unnecessary. That is, instead of retrieving the target data from the data stored in the logging memory 74, the data of the target period can be extracted from the corresponding relationship between the year, month, date, and address of the time information. In other words, the logging memory 74 manages the real-time year, month, date, or time information in the RTC 68, and this time information, that is, the real-time year, month, date, and stored data correspond one-to-one. Since the data of the target period can be extracted from the corresponding relationship between the time information and the address, it is easy to generate information representing the history in the display range set by the user, that is, the time width, that is, the integrated flow rate.

As described above, the display unit 4 has a real-time clock (RTC) 68 that functions as a real-time clock, and power can always be supplied via the first cable 30 connected to the display unit 4. Therefore, data can be stored seamlessly in the logging memory 74 in association with the time information of the RTC 68 . The data stored in the logging memory 74 may be copied to a non-volatile recording medium such as an SD card.

In the total integrated flow rate buffer 88 and the total integrated leak amount buffer 98, when the number of digits of the buffer is exceeded, overflow processing is performed to integrate from 0 (zero). Also, the integrated flow rate for each segmented region M(n) can be obtained from the difference in the total integrated flow rate at each time as will be described later, but the difference becomes negative in the case of overflow. When the difference is negative, it is assumed that an overflow has occurred, and the total difference integrated amount is calculated. If an overflow occurs in each segmented area M(n), an accurate integrated flow rate cannot be calculated. It is preferable to set the buffer size (the number of digits) so that the number of digits overflows once or less in the segmented area M(n). For example, if each segmented area M(n) is in units of one month, by setting the buffer size (number of digits) to the extent that the overflow occurs once or not in units of years, It is possible to prevent overflow from occurring.

Regarding the difference calculation and overflow processing, referring to FIG. (1:00:00 to 1:59:99) usage amount is from December 31, 2020 2:00 (2:00:00 to 2:59:99) total accumulated flow rate 9,999,757 to December 2020 Calculate the difference of 9,999,312 in the total integrated flow rate between 1:00 and 31st, and calculate as 445. Also, on December 31, 2020, the total accumulated flow rate overflowed at 2:00 (overflow at 10,000,000), and the total accumulated flow rate decreased at 3:00. 10,000,000 is added to the total integrated flow rate at the time of the hour to obtain the difference, which is calculated as 460. In addition, the usage amount on December 31, 2020 is the difference between the total accumulated flow rate of 13,424 (overflow processing 10,013,424) at 0:00 on January 1, 2021 and the total accumulated flow rate of 9,999,156 at 0:00 on December 31, 2020. is calculated as 14,268.

With reference to FIG. 8, the outline of the display using the color liquid crystal, which is the display device of the display unit 4, will be described. The color liquid crystal 38 has a rectangular shape, and the display screen of the color liquid crystal 38 consists of a main display area 38a in the center in the vertical direction, a header display area 38b above it, and a footer display area 38c below the main display area 38a. and are set.

FIG. 9 is a diagram for explaining an example of items displayed in the main display area 38a. In the main display area 38a, in addition to the instantaneous flow rate (current value) display in which the numerical value of the instantaneous flow rate is displayed, the history display of the display range that is set by the user, that is, the time width, the graph display of the gas usage amount for each section, , a historical numerical display of the amount of gas used for each section can be displayed. These display items may be displayed simultaneously, or may be selectively displayed based on the user's operation. By displaying the current value and the history at the same time, the user can grasp the past history while grasping the current situation. When the user changes the setting of the display range, that is, the time width, the history display is changed accordingly.

FIG. 10 is a diagram for explaining the graph display of the history, based on the total integrated flow rate associated with the time stored in the logging memory 74, for each time division (in the illustrated example, one hour) A bar graph corresponding to the integrated flow rate (usage amount) corresponding to is displayed. FIG. 11 is a diagram for explaining the graph display of each date/time division in the case of the display range including the present. The bar graph displayed in the current date and time division is based on the total integrated flow rate held in the total integrated flow rate buffer 88 and the latest total integrated flow rate among the total integrated flow rates linked to the time stored in the logging memory 74. , and increases moment by moment according to the update of the total integrated flow rate held in the total integrated flow rate buffer 88 . In other words, in addition to the bar graph corresponding to the current date/time segment from 2:00 to 3:00, the total integrated flow associated with the time stored in the logging memory 74 corresponds to the past date/time segment from 0:00 to 2:00. A bar graph can be displayed. Since it is displayed in time divisions with high periodicity and regularity, it is easy to compare with past conditions. This facilitates quantitative comparison with the past state even if the correct value of the amount used in the normal state is not known, so that gas such as compressed air can be easily managed.

In the display of the display range including the present, a bar graph of the history for each corresponding date/time segment in the past period range may be superimposed and displayed at the position of the corresponding date/time segment. In this superimposed display, it is preferable to adopt, for example, different colors or a semi-transparent display mode to facilitate discrimination from the history bar graph. When the user changes the setting of the display range, that is, the time width, based on the total integrated flow rate associated with the time stored in the logging memory 74, the display is immediately switched to the corresponding graph display.

In the display related to history display, the date corresponding to the display period is displayed. If the day is selected, the year/month/day is displayed, if the month is selected, the year/month is displayed, and if the year is selected, the year is displayed. Referring to FIG. 8, the selection of the display item of the target period can be performed with the menu button 40 and the up/down/left/right buttons 42a of the operation unit 42, and the selected change can be confirmed with the SET button 42b.

As a segment corresponding to the display range (time width) of the graph display, if the day is selected as the display range, the total integrated amount for each segment (0:00 to 24:00) for each hour of the day is preferable. is displayed as a bar graph as a history graph display. A line graph may be displayed instead of the bar graph. Moreover, a bar graph and a line graph may be selectable. If the month is selected as the display range, the division of the month, that is, the total integrated amount for consecutive days from the 1st to the 31st is displayed in a bar graph. A line graph may be displayed instead of the bar graph. If a year is selected as the display range, each segment of the year, that is, the total integrated amount for consecutive months from January to 12th is preferably displayed in a line graph. A bar graph may be used instead of the line graph.

Regarding the graph display, it may be possible to select a display range of week, half term, morning, afternoon, and a limited time span (for example, 3 hours). If a week is selected as the display range (time width), a bar graph is displayed as a history graph of the total integrated amount for each consecutive day of the week as a division of the week. A line graph may be displayed instead of the bar graph. If a half term is selected as the display range (time width), the total integrated amount for each week, ie, weeks 1 to 26, is displayed as a bar graph for each segment of the corresponding half term. A line graph may be displayed instead of the bar graph. When the display range of morning or afternoon is selected, for example, the total integrated amount for every 30 minutes is displayed as a bar graph. A line graph may be displayed instead of the bar graph. For example, when a display range (time width) of 3 hours is selected, the total integrated amount for each 10 minutes, for example, is displayed as a bar graph. A line graph may be displayed instead of the bar graph.

It may be selectable whether to display a bar graph or a line graph. Also, it may be possible to select whether to display graphs or numerical values. Moreover, the graph display and the numerical display may be switchable for display.

A first display range that includes a date and time segment including the current time and one or more past date and time segments that are continuous therewith, and a second display range that includes a plurality of continuous date and time segments that are older than the first display range. and can be switched during flow measurement operation. After this switching operation, the integrated flow rate data corresponding to each date/time division is immediately displayed in a graph. After the display of the second display range, the display may be automatically switched to the display of the first display range when the user does not perform any operation for a certain period of time.

In the header display area 38b, information that is convenient to display over a plurality of screens, for example, the stability of flow rate measurement is displayed in a graph or a bar, and an arbitrary character string is displayed with reference to FIG. , for example, to display character strings set by the user and to display the communication status.

The footer display area 38c is used to display an operation guide, for example. A specific example is illustrated in FIG. For example, a circle-shaped icon representing the SET button 42b is displayed for screen setting, and a pair of right and left triangular icons representing left and right operations of the up, down, left, and right buttons 42a are displayed to change the date, month, and year. Is displayed.

14 to 18 show specific examples of display. FIG. 14 shows a display screen displaying the instantaneous flow rate. When this display screen is called a "simple screen", the simple screen display displays the instantaneous flow rate (current flow rate value) in the main display area 38a of the color liquid crystal 38, for example, "5,258.71". In addition, threshold values H1 and L1 for the first output and threshold values H2 and L2 for the second output are numerically displayed in the main display area 38a. In this display example, two thresholds H1 and L1 are provided for each output, but one threshold may be provided.

If there are two threshold values, H and L, as in the example shown in the figure, it may be set to turn ON when the instantaneous flow rate (current value) is between H and L. It may be set to turn off when (current flow rate value) is between H and L. If there is one threshold, it may be set to turn ON when the instantaneous flow rate (current flow rate value) exceeds the threshold value, or vice versa. It may be set to turn OFF when the value is exceeded. It is desirable to be able to set a threshold for each output, that is, select two thresholds or one threshold, select which state to turn on, and set the threshold. These selections and settings can be made by operating the menu button 40 and the operation button 42 during the flow measurement operation.

Here, in addition to the volumetric flow rate (actual flow rate) in the measured state, it is possible to select whether to display the volumetric flow rate (normal flow rate) in the standard state or the converted flow rate such as the standard flow rate with a reference temperature of 20°C. These selections can often be made by operating the menu button 40 and the operation button 42 .

The integrated flow rate may also be numerically displayed in the main display area 38a. It may be possible to select whether or not to display this integrated flow rate. Here, the integrated flow rate is the integrated flow rate from the time when a reset signal is input by an external trigger input or button input. It may be possible to select whether or not to display the usage amount and the leak amount instead of the integrated flow rate. These selections can be made by operating the menu button 40 and the operation button 42 .

A graph display 110 imitating a measurement stability indicator is displayed in the header display area 38b. A bar display may be used instead of the graph display 110 . This graph display 110 indicates whether or not the flow rate is stably measured.

The header display area 38b further displays communication information 112 of "communication A" and "communication B." Communication A means, for example, USB communication, and communication B means, for example, IO-LINK communication.

An ON/OFF output indicator lamp 114 is also displayed in the header display area 38b. The illustrated example includes a first output indicator lamp 114a and a second output indicator lamp 114b, the first output indicator lamp 114a being ON and the second output indicator lamp 114b being OFF.

The threshold for each output can be set by operating the menu button 42 according to the icon 116 displayed in the footer display area 38c to call a submenu and set the threshold in this submenu.

In the description of the display screens in FIG. 15 and subsequent figures, common displays are denoted by the same reference numerals, and the description thereof is omitted. FIG. 15 shows a screen that simultaneously displays a bar graph of usage and numerical values. In the header display area 38b, a usage amount display range (period range) 118 is displayed in terms of year, month, and day. The screen shown in FIG. 15 shows the case of the unit of "day". Here "2018" means the year, "10" means October, and "12" means the 12th. If the display is in units of "month", "2018/10" is displayed, and if it is in units of "year", it is displayed as "2018". For example, in the case of "week" unit, it is better to display like "2018/35-36 week". To set the display range (period range), that is, to set the time width, the submenu is selected by operating the menu button 40 according to the submenu icon 116 displayed in the footer display area 38c, and the submenu displayed thereby. can be set from This setting change can be made during the flow measurement operation, and the setting change of the display range is immediately reflected in the graph display of the integrated flow rate. In the submenu, for example, options of "day", "month", and "year" may be displayed, and one of the three options may be selected. Also, in the submenu, one display language may be selected from a plurality of options.

The display screen of FIG. 15 shows a case where the display range is in units of "days" and the division is in units of "hours" as described above. Each bar graph is therefore displayed in units of time. The scale width of the bar graph is automatically scaled according to the maximum amount of use among the amounts of use in each segment within the display range.

When the display range is in "month" units, the division is in "day" units, and when the display range is in "year" units, the division is in "month" units. In the case of the "week" unit, the division is the "day" unit. These display ranges, ie, time widths, can be changed even during operation of flow measurement.

The display screen shown in FIG. 15 numerically displays the cumulative usage amount (the flow rate integrated from 0 o'clock to the current time) within the display range. That is, the total amount of usage displayed in the bar graph of the usage amount displayed in the bar graph is numerically displayed. If the display range is in units of "month", the total amount of usage for that month is displayed numerically. If the unit is "year", the total usage amount for that year is displayed numerically. When the current time is included in the display range, the usage amount increases every moment according to the (instantaneous) flow rate.

The usage amount displayed in the main display area 38a means the integrated value of the flow rate (integrated flow rate) in each section. The "integrated flow rate" described with reference to FIG. 14 is the integrated value from the time when the reset signal is input. FIG. 15 shows the state in the 18:00 period, and the bar graph in the 18:00 period is extended every moment according to the instantaneous flow rate (current usage amount). On the other hand, the bar graph from 0:00 to 17:00 (from 0:00 to 18:00) shows the past state (history of usage). Preferably, historical values and current values (usage in the 18:00 period) are displayed in different colors.

A date change icon 120 is displayed in the footer display area 38c. This icon 120 is composed of a pair of triangles pointing to the left and right, and by operating the left and right buttons 42a of the operation button 42, which means the pair of triangle icons 120, the date in the display range (period range) can be changed. can do. For example, if you change to "2018/10/11" on the previous day, the past status (usage history) will be displayed for all from 0:00 to 23:00 (0:00 to 24:00).

In the main display area 38a, in addition to the usage amount, simultaneous display of usage amount + leak amount, display of leak amount, and the like can be selected. This display content can be selected by selecting a submenu and selecting a display item from the submenu.

The display screen shown in FIG. 16 displays the amount used numerically. In the main display area 38a, both the classified usage amount and the cumulative usage amount (the flow rate integrated from 0 o'clock to the current time) within the display range are numerically displayed.

The display screen shown in FIG. 17 simultaneously displays a usage amount comparison graph in which the usage amount in the first display range and the usage amount in the second display range are displayed superimposed, and the numerical value of the usage amount ratio. The usage comparison graph is displayed as a line graph, and in the display range of the line graph to be compared, if the display range includes the current time, it is exactly that day, month, and year, so it is not necessarily displayed. good. The display range can be set by selecting a submenu and setting from the submenu.

This setting change is accepted even if the user operates the operation unit 42 during the flow measurement operation, and the setting change of the display range is performed. Then, the graph display corresponding to this is changed. After that, when a period of no user operation continues for a certain period of time, the display range may be automatically switched to the original display range.

Furthermore, after switching the setting from the first display range to the second display range, when the display range is switched to the third display range by the user's operation, the usage graph corresponding to the first display range and the third display range The usage amount graph corresponding to the display range may be displayed for comparison by aligning the display positions of the display range.

In the usage amount comparison graph, a line graph of the historical usage amount in a specific past display range and a line graph of the usage amount in the display range including the current time are superimposed and displayed. That is, two types of line graphs are displayed along a common axis. A line graph to be compared may be displayed as a ghost. The usage amount comparison graph shows the usage amount from the start of the display range to the relevant time (flow rate integrated from 0:00 to the relevant time), which corresponds to the sum of the classified usage amounts. Preferably, a vertical dashed line indicating the current position is displayed. Also, on each line graph, a circle mark may be displayed at the point where it intersects with the vertical dashed line indicating the current position.

As a modification, the same segment (same relative segment: for example, 18:00) in different display ranges may be comparatively displayed. Further, by operating the operation button 42, the date to be compared may be changed. In this case, the display range including the current time and the comparison target after the change are displayed for comparison.

The usage ratio can display the ratio of the same segment (same relative segment: for example, 18:00) in different display ranges. The current usage amount (flow accumulated from 0 o'clock to the current time) is displayed as a percentage when the usage amount in the same category to be compared is set to 100. As a modification, the current usage amount may be displayed as a percentage when the total usage amount (the usage amount at 24 hours) in the display range to be compared is set to 100.

Although the display screen in FIG. 17 displays information related to the usage amount, it can be switched to display information related to the leak amount by the user's operation (submenu). In this leak amount display, the leak amount history comparison graph and the numerical value of the leak amount ratio are displayed at the same time.

On the display screen of FIG. 18, for example, a bar graph of the usage amount in the plus direction and the minus direction in the loop piping and its numerical value are displayed at the same time. Here, the bar graph of the usage amount in the positive direction, in the example shown, shows the cumulative usage amount for each segment of one hour. is defined as minus, and means the flow rate in the plus direction of the sum of the flow rates in the plus and minus directions separately, and the flow rate in the minus direction is displayed as a bar graph of the minus usage amount. In the illustrated display example, the bar graph positioned above the horizontal axis (time axis) indicates the cumulative usage amount for each hour in the positive direction, and the bar graph positioned below indicates the load usage amount for each hour in the negative direction. indicates

The "+" shown in the numerical display of the amount of usage displayed in the main display area 38a of the display screen in FIG. is the total amount used in the display range, that is, the integrated value of the amount used.

Displaying both the positive and negative directions of usage separately is useful, for example, when compressed air is delivered between factories, or when there is forward flow (plus direction) and reverse flow (minus direction) such as in loop piping. It can be used for management when obtaining. 14 to 18, the display device of the display unit 4, that is, the color liquid crystal 38, can be used to supply not only the instantaneous flow rate but also various information to the user. As a result, the user can directly use the information displayed on the color liquid crystal 38 to perform reasonable and rapid factory management without having to process the displayed data or information.

The different display screens exemplarily described with reference to FIGS. 14-18 can be switched by user selection. This display switching will be described with reference to FIG. 19, the same reference numerals are given to the same elements as those described with reference to FIG. 6, and the description thereof will be omitted. The display processing engine 100 executes processing for switching the display screen of the color liquid crystal 38 by the user operating the operation units 42 and 44 . The logging memory 74 stores the data of each section by associating the top address with the real time. For this reason, when changing the display contents along with the display switching, the past data calculates the difference in the total integrated flow rate between each section, and the current data is the latest value of the logging memory 74 and the total integrated flow rate. By calculating the difference from the value in the buffer 88 (FIG. 5), the display data after the display screen is switched is created and displayed.

By operating the operation units 42 and 44 of the display unit 4, it is possible to easily change the date, change the display range (time width), change the display contents (leak amount, comparative display), etc., without using an external PC. be able to. Then, the user can display necessary information on the color liquid crystal 38 of the display unit 4 by setting the operation units 42 and 44 by simple operations, and obtain useful information, for example, for management of usage amount. .

20 to 22 show display examples of display screens related to leak amount display. On the display screen shown in FIG. 20, the leakage amount is displayed as a graph and numerical values. Specifically, the accumulated leak amount for each time period (every hour in the illustrated example) is displayed as a bar graph, and the total accumulated leak amount within the display range is numerically displayed.

The display processing engine 100 (FIG. 5) compares the total leak accumulated amount held in the total leak accumulated amount buffer 98 with the latest total leak accumulated amount out of the total leak accumulated amounts linked to the time stored in the logging memory 74. A display screen is generated that graphically displays the integrated leak amount determined based on the corresponding date/time segment.

The total leak accumulated amount held in the total leak accumulated amount buffer 98 (FIG. 5) is updated moment by moment, and the display processing engine 100 displays the graph at the position of the corresponding date and time segment based on the updated total leak accumulated amount. Generate a display screen to display. As the total accumulated leak amount and the display screen are updated, the bar graph G1 (FIG. 20) of the accumulated leak amount displayed in the current date and time segment gradually expands according to the update.

In addition, the display processing engine 100 calculates the leak amount for each date and time segment determined based on each total leak integration amount for each date and time segment corresponding to the display range, out of the total leak integration amount associated with the time stored in the logging memory 74. A display screen is generated that displays the integrated amount as a bar graph at the position of the corresponding date/time section of the display graph of FIG. 20, for example. As a result, each accumulated leak amount corresponding to each past date and time segment and the accumulated leak amount corresponding to the current date and time segment are displayed at the same time with high regularity.

Since it is displayed in time divisions with high periodicity and regularity, it is easy to compare with past conditions. As a result, even if you do not know the correct value of the integrated leak amount in the normal state, it becomes easy to make a quantitative comparison with the past history state, making it easier to manage gases such as compressed air. Become.

A date change icon 120 is displayed in the footer display area 38c. This icon 120 is composed of a pair of triangles pointing to the left and right, and by operating the left and right buttons 42a of the operation button 42, which means the pair of triangle icons 120, the date in the display range (period range) can be changed. can do. For example, if you change to "2018/10/11" on the previous day, the past status (usage history) will be displayed for all from 0:00 to 23:00 (0:00 to 24:00).

In other words, the display processing engine 100 calculates the total leak accumulated amount associated with the time stored in the logging memory 74 for each date and time segment corresponding to the display range (period range) instructed via the operation button 42. A display screen is generated that graphically displays the integrated leak amount for each day and time segment determined based on the integrated leak amount, at the position of the corresponding day and time segment.

To set the display range (period range), that is, to set the time width, the submenu is selected by operating the menu button 40 according to the submenu icon 116 displayed in the footer display area 38c, and the submenu displayed thereby. can be set from This setting change can be made during the flow rate measurement operation, and the setting change of the display range is immediately reflected in the graph display of the integrated leak amount. In the submenu, for example, options of "day", "month", and "year" may be displayed, and one of the three options may be selected.

FIG. 21 shows a display screen that simultaneously displays the usage amount in the display range, the usage amount corresponding to each date/time segment (every continuous hour in the illustrated example), and the integrated leak amount. The total usage of the display range is numerically displayed at the bottom of the main display area 38a. The usage amount corresponding to each date/time segment is displayed in the upper part of the main display area 38a in a color-coded bar graph containing the leak integrated amount for each continuous hour corresponding to each date/time segment. The numerical value of the usage amount in the display range is displayed in the upper part of the main display area 38a, and indicates the usage amount in the time width from the start of the display range to the relevant time (flow rate integrated from 0:00 to the relevant time). , corresponds to the accumulated amount of usage corresponding to each day and time segment, and the transition of this usage amount is displayed by a line graph LG.

The usage amount corresponding to each day/time segment and the accumulated leak amount displayed superimposed are the integrated values of the leak flow rate in each day/time segment, and are displayed in a bar graph. In the graph display, the integrated leak amount and the usage amount are displayed aligned on a common graph axis, and preferably displayed in different colors. That is, regarding the superimposed display of the usage amount and the integrated leak amount, the display range is shared and the first vertical axis at one end of the display range is shared.

As described above, the display processing engine 100 determines based on the total integrated flow rate held in the total integrated flow rate buffer 88 and the latest total integrated flow rate out of the total integrated flow rate associated with the time stored in the logging memory 74. The usage amount is graphically displayed at the position of the corresponding date and time division, and the latest integrated leak amount among the total leak integrated amount held in the total leak integrated amount buffer 98 and the total leak integrated amount linked to the time stored in the logging memory 74 is displayed. A display screen is generated that graphically displays the leak accumulated amount determined based on the total leak accumulated amount and the corresponding date division.

The total integrated flow rate held in the total integrated flow rate buffer 88 and the total leak integrated amount held in the total integrated leak amount buffer 98 are updated moment by moment, and the display processing engine 100 displays the updated total integrated flow rate and total leak integrated amount. Based on the amount, a display screen is generated that graphically displays at the location of the corresponding time period. By updating the total integrated flow rate, the total integrated leak amount, and the display screen, the bar graphs of the usage amount and the integrated leak amount displayed in the current date/time segment grow every moment according to the update.

In addition, the display processing engine 100 calculates the usage amount for each date and time segment determined based on each total integrated flow rate for each date and time segment corresponding to the display range, out of the total integrated flow rate associated with the time stored in the logging memory 74. , is displayed in a graph at the position of the corresponding date and time segment, and among the total leak integrated quantity linked to the time stored in the logging memory 74, each determined based on each total leak integrated quantity for each date and time segment corresponding to the display range A display screen is generated that graphically displays the integrated leak amount for each day/time segment at the position of the corresponding date/time segment. As a result, each usage amount and each accumulated leak amount corresponding to each past date and time section and the usage amount and each leakage accumulated amount corresponding to the current date and time section are displayed at the same time with high regularity.

Line graph LG (Fig. 21) The amount of usage in the displayed range is displayed as a percentage when the target amount of usage is set by the user in advance and the target amount of usage is set to 100. The vertical axis VL1 (unit: m ³ ) and the second vertical axis VL2 (unit: %) are configured in different units. It is preferable to display the target usage amount, and in this case, it is preferable to display the target usage amount by, for example, a horizontal dashed line. Similarly, the target values of the usage amount and the integrated leak amount for each date and time segment displayed as bar graphs may also be displayed as horizontal dashed lines. In FIG. 21, "Use" indicates the target value of the usage amount, and "Leak" indicates the target value of the integrated leak amount.

Two vertical axes VL1 and VL2 with different units are referenced for the usage amount in the display range, and the usage amount and integrated leak amount for each day/time segment. Target values that refer to different vertical axes are displayed simultaneously. If so, it may be difficult to grasp at a glance which vertical axis is being referred to. Therefore, the target usage amount for the usage amount of the display range displayed in percentage is substituted by the display of 100 on the second vertical axis VL2, and a line indicating whether or not the target usage amount is exceeded indicates the usage amount of the display range. The color of the line of the graph LG may be varied above and below the target usage amount Use. It is preferable to use different colors to display the usage amount and the integrated leak amount for each day and time and each target value.

The amount of use numerically displayed in the lower part of the main display area 38a is preferably the total amount of use within the display range (the flow rate integrated from 0 o'clock to the current time). In other words, the total amount of each usage in the usage graph displayed at the top is numerically displayed.

The screen display in FIG. 22 is the leak rate. The leak rate means the ratio of the leak amount in the display range to the usage amount or the integrated flow rate. This leak rate is preferably displayed numerically, and the ratio between the usage amount and the leak amount is displayed circularly.

The calculation of the leak amount by the leak amount processing engine 92 (FIG. 5) can be obtained by the following method. That is, the flow rate is measured, the fluid non-use period and the fluid use period are determined based on the measured flow rate, and the leak amount during the fluid non-use period is determined based on the flow rate during the fluid non-use period. The leak amount processing engine 92 sends the determined leak amount to the leak amount buffer 94 and updates the leak amount held in the leak amount buffer 94 . The leak amount processing engine 92 discriminates between the fluid nonuse period and the fluid use period based on the measured flow rate, and does not update the leak amount held in the leak amount buffer 94 when the fluid use period is discriminated.

As a result, the integrated leak amount processing engine 96 (FIG. 5) obtains the integrated leak amount based on the leak amount that is sequentially updated during the fluid non-use period, and during the fluid use period, the fluid non-use immediately before the fluid use period A leak integrated amount is obtained based on the leak amount in the period. That is, the integrated leak amount processing engine 96 estimates based on the flow rate in the past fluid non-use period, and calculates the determined leak amount in the fluid non-use period, the estimated leak amount in the fluid use period, and the elapsed time of each. Calculate the integrated leak amount based on The integrated leak amount processing engine 96 sends the calculated integrated leak amount to the total integrated leak amount buffer 98 and updates the total integrated leak amount held in the integrated total leak amount buffer 98 .

The leak rate processing engine 92 may set a first threshold for distinguishing between periods of no fluid use and periods of no fluid use, and based on the measured flow rate and the first threshold, no fluid use period may be determined. Periods and fluid use periods can be discerned. In addition, the leak amount processing engine 92 may issue an alarm when the leak amount becomes abnormally large. should be set.

In the display screen described with reference to FIG. 20, it is preferable to simultaneously display the integrated amount of leakage in the display range and the amount of money when this amount is converted into a cost. That is, in the case of a compressed air leak, it is preferable to display the cost to be paid for the driving power of the compressor required to generate the compressed air of the total leak integrated amount together with the total leak integrated amount. By converting it into a cost and displaying it, the user will be able to feel the economic loss with a sense of reality, and will be quick to take countermeasures against the leak.

Regarding the determination of the amount of leak, for example, if all the devices in the factory that use compressed air as a drive source are stopped and compressed air is flowing through the pipe P at that time, it can be estimated that it is caused by the leak. However, it is not always easy to detect and estimate the amount of leakage, because the period during which all devices can be intentionally stopped is limited to late nights and holidays, for example.

In FIG. 23, the leak amount processing engine 92 determines a reference leak amount when a certain condition is satisfied, and based on this determined leak amount, the leak integrated amount processing engine 96 determines whether the facility is in operation or not. 4 is a time chart for calculating the total leak integrated amount for the period. To explain the outline with reference to FIG. 23, the leak amount determination mode is entered when a certain condition is satisfied. As a certain condition, a threshold value is set at which it can be assumed that the factory equipment has entered a dormant state. This leak amount determination mode is continued until the factory equipment is operated next time, that is, until a certain condition is no longer satisfied. A second condition may be set for determining that the factory equipment has been operated, and the leak amount processing engine 92 may determine that the factory equipment has been operated based on the second condition. The leak amount determined in the leak amount determination mode is used to calculate the integrated leak amount during the period of the leak amount determination mode and during the operation period of the factory equipment immediately thereafter. Preferably, the integrated leak amount is obtained for each day and time segment described above, and the integrated leak amount for each segment is displayed. As the leak amount during the operating period of the factory equipment, the leak integrated amount may be obtained by assuming that the above leak amount corresponds, or the internal pressure of the pipe P during the operating period of the factory equipment is detected and corrected by this internal pressure. The value may be used to obtain the integrated leak amount.

As a modification, the leak rate processing engine 92 determines that when the measured flow rate falls below the leak threshold for determining the leak rate, the compressed air is not being used, i.e., the plant has entered a dormant state. During the period (non-use period) during which the leak threshold value is exceeded, for example, every predetermined period, for example, every 90 seconds, an average value is obtained, and this average value is sequentially updated as the leak amount. The last updated leak rate may be considered to have occurred until the flow rate is above and below the leak threshold. In this case also, based on the leak amount obtained during the non-use period determined based on the leak threshold value, The accumulated leak amount is obtained for each day and time segment during the operating period, and the accumulated leak amount for each segment is used to calculate the displayed leak amount. Preferably, the integrated leak amount is obtained for each day and time segment described above, and the integrated leak amount for each segment is displayed. Also in this modification, when the leak amount that is sequentially updated exceeds a predetermined abnormality threshold value during the non-use period, it may be determined that some abnormality has occurred, and an alarm may be output.

Aside from the leak amount determination that is automatically performed as described above, it may have a second leak amount determination mode in which the leak amount is determined based on timing input from the outside. During the second leak rate determination mode, the leak rate processing engine 92 suspends automatic leak rate update by discriminating between periods of no fluid use and periods of fluid use based on the measured flow rate. During the second leak amount determination mode, the leak amount processing engine 92 receives an external timing input, for example, a trigger signal (Tr in FIG. 5) from an external device or a mode change instruction from the user via the operation unit. Then, the flow rate acquired from the instantaneous flow rate buffer 82 when there is a timing input from the outside is sent to the leak amount buffer 94 as the leak amount, and the leak amount held in the leak amount buffer 94 is updated. When the second leak rate determination mode is finished, the leak rate processing engine 92 automatically updates the leak rate by distinguishing between the fluid non-use period and the fluid use period based on the measured flow rate.

More specifically, with reference to FIG. 23, the above leak amount determination mode will be described. Based on the measured flow rate and the threshold value, when the measured flow rate falls below the threshold value, the first leak amount determination mode is entered. When the measured flow rate exceeds the threshold value, the first leak amount determination mode is canceled. During the period of the first leak amount measurement mode, the flow rate is continuously measured, and the average value is determined as the first leak amount BLa(1). The leak amount in the first leak amount calculation period including the first period of equipment operation after the first leak amount determination mode is canceled and the period of the first leak measurement mode is based on the first leak amount BLa(1) Calculated. After that, this processing is repeatedly executed.

An alarm may be output when the measured flow rate becomes abnormally high during the leak amount determination mode, that is, when the measured flow rate exceeds the abnormality detection threshold value.

Processing in the leak amount determination mode will be described with reference to FIG. For the above thresholds, it is always higher when using compressed air under normal operation. For this reason, a threshold is set at which a value less than the flow rate of compressed air under normal operation is regarded as a leak. This leak threshold determines whether compressed air is being used, i.e. when the plant is running, based on the measured flow rate, regardless of whether the plant is running or not running. It is possible to determine whether or not there is

When the measured flow rate falls below the leak threshold, it is determined that no compressed air is being used, and the leak amount determination mode is entered. In the leak amount determination mode, a plurality of continuously measured flow rate values are averaged when the flow rate is stabilized after the leak detection delay time has elapsed, and this average value is determined as the leak flow rate BLa.

Preferably, the averaging period is predetermined, the first average value (“9.5” shown in FIG. 24) at the first averaging time is stored in memory, and the second average at the second averaging time is Update the first average value in memory with the value ("9.8" shown in FIG. 24). Next, the second average value in memory is updated with the third average value ("9.6" shown in FIG. 24) at the third averaging time. The first through third average values for the first through third periods of each time segment can be used to graph this. After the leak amount determination mode ends, the average value continuously updated during the leak amount determination mode is set as the leak flow rate BLa(n). By continuously updating the leak flow rate BLa(n) in chronological order, it is possible to obtain the most probable leak amount contained in the amount of compressed air used during on-site operation. A value obtained by correcting the reference leak flow rate BLa(n) according to the internal pressure of the pipe, the environmental temperature, or the like may be used as the leak amount during operation.

Also, preferably, the leak threshold value may be updated based on the leak flow BLa(n) to optimize the leak threshold. That is, when the reference leak flow rate BLa(n) changes from a predetermined value, an instruction to change the threshold value is given, and when this instruction is received, the threshold value stored in the memory is updated to change the threshold value. You may make it

More specifically, based on the flowchart of FIG. 25, the instantaneous flow rate, that is, the current flow rate is obtained in step S1. In the next step S2, it is judged whether or not this instantaneous flow rate is below the leak threshold. Reset. If YES in step S2, it is determined that the instantaneous flow rate is small, and the process proceeds to step S4 to determine whether the delay time timer is set. An example of the set time of the delay time timer is one minute. If NO in step S4, the process advances to step S5 to set a delay time timer. If the delay time timer is set in step S4, the process proceeds to step S6 to determine whether or not the delay time has passed.

In step S7, it is determined whether or not the average flow rate has been set. If NO, the process advances to step S8 to set the instantaneous flow rate as the average flow rate and set the averaging time timer. An example of the set time of the averaging time timer is 1 minute. If YES in step S7, that is, if the average flow rate has been set, the flow advances to step S9 to obtain a new average flow rate from the average flow rate and the instantaneous flow rate, and set the obtained average flow rate as the new average flow rate. In the next step S10, it is determined whether or not the averaging time has been exceeded. If YES, it is determined that sufficient averaging has been performed, and the flow advances to step S11 to determine whether the leak value is stored. If there is, the flow advances to step S12 to store the leak value in the memory. On the other hand, if YES, the routine proceeds to step S14 to update the average flow rate as the stored leak value, and then to step S13 to reset the average flow rate and reset the averaging time timer.

With the above processing, when the flow rate is stable at a slight value, the average value is regarded as the leak value, and by sequentially updating this, it is possible to automatically obtain a probable leak value at midnight, for example. . Then, the leak value obtained in this manner may be used for the screen display described above.

When obtaining the most probable leak value in the leak amount determination mode in the above procedure, even if chattering occurs near the leak threshold value, the calculation of the automatically calculated leak flow rate is not executed. Also, even if a flow rate that momentarily exceeds the leak threshold value is measured during the leak value detection, the instantaneous flow rate fluctuation does not become a disturbance factor because the delay time is recalculated. Even if the leak rate determination mode is running, for example, even if there is a power failure or the power supply is cut off, the automatically calculated average value, that is, the leak rate, is saved in memory, so the leak rate in this memory is considered to continue. be able to. Note that the median value between the maximum and minimum values may be used instead of the average leak value.

Although a preferred embodiment in which the present invention is applied to a clamp-on type ultrasonic gas flowmeter has been described above, the present invention is not limited to this. For example, gas flowmeters such as thermal flowmeters and vortex flowmeters are known. The present invention can also be suitably applied to these gas flowmeters.

Fm Clamp-on type ultrasonic gas flowmeter P Piping 2 Sensor main body 4 Display unit 6 First ultrasonic element 8 Second ultrasonic element 10 Housing of sensor main unit 36 Waterproof/dustproof case for display unit 38 Display for display unit Color liquid crystal which is a device 40 Menu button of the display 42 Operation button of the display F Hook of the main body of the sensor H Locking hole on the back of the display 48 Microprocessor constituting the flow rate measurement control part of the main body of the sensor 64 Display control of the display Microprocessor constituting part 68 RTC (real time clock) of display part
70 Backup battery for display 74 Logging memory for display

Claims (5)

a flow rate measuring means for measuring the flow rate of the fluid in the pipe;
a calculation means for determining a leak amount based on the flow rate measured by the flow rate measurement means under certain conditions and calculating an integrated leak amount for each predetermined date and time segment;
a display screen generating means for generating a display screen for graphically displaying an integrated leak amount corresponding to each date/time segment in a display range composed of a plurality of date/time segments;
and a display for displaying the graph display screen generated by the display screen generation means. 2. The gas flow meter according to claim 1, wherein said display unit simultaneously displays the total integrated leak amount in said display range and the money amount when this amount is converted into money. 2. The gas flowmeter according to claim 1, wherein said display unit displays a leak amount comparison display in which leak accumulated amounts corresponding to respective date divisions of said different display ranges are superimposed and displayed. 2. The gas flow meter according to claim 1, wherein said display unit simultaneously displays an integrated flow rate and a leak amount corresponding to each date and time division of said display range. 2. The gas flow meter according to claim 1, wherein the display displays a leak rate, which is a ratio of the leak amount in the display range to the integrated flow rate.

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