JP4639633B2 - Spectrophotometer - Google Patents

Description

  The present invention relates to various spectrophotometers such as an ultraviolet-visible spectrophotometer, an infrared spectrophotometer, a fluorescence spectrophotometer, and more specifically, to observe temporal changes in absorbance, transmittance, etc. for the same sample. The present invention relates to a spectrophotometer that automatically performs repeated continuous measurements such as sequentially measuring a plurality of samples.

  If an ultraviolet-visible spectrophotometer or the like is used, the absorbance spectrum or transmittance spectrum of the sample solution can be measured, and the component contained in the sample solution can be specified from the spectrum, or the content of the component can be estimated. . In such a spectrophotometer, in order to see temporal changes due to chemical reactions of components in a sample, continuous measurement is often performed repeatedly at predetermined time intervals over a relatively long time. In the conventional general spectrophotometer, in such repeated continuous measurement, if the measurer inputs and sets the measurement time interval and the measurement end time (or the number of measurement repetitions) before the measurement, the measurement time until the measurement end time is reached. Repeated continuous measurement is automatically executed at intervals (see, for example, Patent Document 1).

  One such ultraviolet-visible spectrophotometer is a photodiode array spectrophotometer (hereinafter referred to as a PDA spectrophotometer). In the PDA spectrophotometer, the intensity of the light wavelength-dispersed by the spectroscope is detected almost simultaneously by a PDA detector in which a large number (for example, 512) of light receiving elements are arranged on a straight line and converted into an electric signal. Therefore, it is not necessary to rotate the spectroscope one by one in order to perform wavelength scanning, and a spectrum in a predetermined wavelength range can be acquired in a short time. Therefore, it is particularly suitable for measuring changes in the spectrum or absorbance of a measurement object that may cause a sudden change in a short time. The conventional general repeated measurement procedure in the PDA spectrophotometer is as follows.

  First, before starting the measurement, the measurer determines basic measurement conditions (hereinafter referred to as basic measurement conditions) and inputs them from the operation unit. Basic measurement conditions include the PDA detector charge accumulation time, data output time interval, number of data integrations, etc. as the time axis conditions, and the horizontal axis conditions as the horizontal axis range (for example, the upper limit wavelength and lower limit wavelength), the horizontal axis unit (Wavelength or wave number), horizontal axis spacing, and the like. When the basic measurement conditions as described above are set, measurement of reference data necessary for the measurement is performed before the measurement for the actual measurement object is performed. That is, the dark current data of the PDA detector is acquired in a state where light incident on the PDA detector is shielded, and the standard state in which there is no absorption by the sample (a reference sample such as air or a pure solvent is filled in the sample chamber). Baseline data (transmittance 100% or absorbance 0 Abs data) is acquired and stored.

  Since some of the basic measurement conditions as described above, such as charge accumulation time, affect the measurement results of the reference data, the basic measurement conditions for acquiring the reference data are input in advance by the measurer as described above. Is set according to the basic measurement conditions. Thereby, accurate reference data can be obtained. Thereafter, in response to an instruction from the measurer or a control signal from an external device or the like, continuous measurement for the measurement object is started. During continuous measurement, each measurement is performed in accordance with the basic measurement conditions set in advance by the measurer as described above.

  The inventor of the present application has proposed a spectrophotometer capable of changing the measurement time interval in such repeated continuous measurement in Japanese Patent Application Nos. 2003-105487 and 2004-43961. According to such a spectrophotometer, for example, when the change in the measurement object is abrupt, it can be narrowed at the measurement time interval to accurately grasp the mode of the abrupt change, while when the change is slow, the measurement time By widening the interval, the amount of data collected can be suppressed and the required capacity of the data memory can be reduced.

  Since repeated continuous measurement in a conventional PDA spectrophotometer is performed according to the procedure described above, the basic measurement conditions for each measurement during continuous measurement are fixed to those input before the measurement. However, depending on the measurement purpose and measurement target, if you want to change the basic measurement conditions during such continuous measurement, in other words, you may need to change the basic measurement conditions to obtain a more appropriate result. .

As an example, the longer the charge accumulation time of the PDA detector, the more minute light can be detected and the detection sensitivity is improved. On the other hand, the output is saturated when the charge accumulation time is increased in the situation where the incident light intensity is high. not obtained accurate photometry value by. Therefore, the measurer determines the charge accumulation time after assuming the change state of the object to be measured to some extent. You may not get highly accurate results. Further, if a sudden change occurs more than expected, there is a possibility that a measurement result that can sufficiently grasp the target change state cannot be obtained under the basic measurement conditions inputted in advance. As another example, for the measurement wavelength range and the measurement wavelength interval, the measurement wavelength interval may be wide in the repeated measurement that lasts for a predetermined time. There may be a time zone that the user wants to see within the wavelength range for each minimum wavelength interval determined by the number of light receiving elements of the PDA detector.

  As described above, the reference data needs to be measured under basic measurement conditions. Therefore, if you want to change the basic measurement conditions during repeated continuous measurements in a conventional PDA spectrophotometer, you need to temporarily stop the current measurement and perform preparations for performing measurements under the new basic measurement conditions. There is. That is, resetting of the time axis and the horizontal axis, recalculation of the horizontal axis conversion table, remeasurement of dark current data and baseline data, and the like are performed as necessary. Since such preparatory work takes time, the continuous measurement is substantially interrupted during that time. In other words, in the flow of continuous measurement time for the measurement target, the measurement time interval will be large in the vicinity of the time when the basic measurement conditions are changed. If you do not want to change the basic measurement conditions, for example, in applications where the real-time nature of the measurement results is important, the basic measurement conditions cannot be changed.

Japanese Patent Laid-Open No. 10-221168 (stage [0012])

  The present invention has been made to solve the above-mentioned problems, and its main purpose is to minimize the time required for changing the basic measurement conditions even when the basic measurement conditions are changed during repeated continuous measurement. Accordingly, it is an object of the present invention to provide a spectrophotometer capable of repeatedly performing continuous measurement while appropriately changing basic measurement conditions without undesirably increasing a measurement time interval. Another object of the present invention is to automatically change such basic measurement conditions without bothering the measurer during measurement when it is desired to change the basic measurement conditions according to predetermined conditions during repeated continuous measurement. It is to provide a spectrophotometer as performed.

The spectrophotometer according to the present invention, which has been made to solve the above problems, is a spectrophotometer that performs continuous measurement multiple times on the same or multiple samples,
a) At least one basic measurement condition of the charge accumulation time of the photodiode array detector, the number of data integrations, or the parameter on the horizontal axis of the spectrum is used or may be used at the time of each spectrum measurement in repeated continuous measurement. An input means for a measurer to input a plurality of certain values;
b) Information necessary for executing data processing corresponding to spectrum measurement under a plurality of types of values for at least one basic measurement condition input by the input means, before the repeated continuous measurement is executed. In addition, information collecting means for collecting each of the plurality of types of values and storing them in the reference data storage means,
c) Evaluation function storage means for storing a predetermined evaluation function for judging a specific fluctuation state of the measurement value with respect to time,
d) evaluation value calculation means for calculating an evaluation value from the measurement value using the evaluation function stored in the evaluation function storage means for each measurement during the execution of repeated continuous measurement;
e) While performing the repeated continuous measurement, while changing the set value of the basic measurement condition using the evaluation value calculated by the evaluation value calculating means or the judgment result of the evaluation value in light of a predetermined reference as the measurement condition changing condition Measurement control means for performing spectrum measurement;
f) The information corresponding to the spectrum measurement under the set value of the basic measurement condition set by the measurement control means is read from the reference data storage means, and the data acquired by each spectrum measurement is read Data processing means for executing data processing using the information,
It is characterized by having.

In a spectrophotometer according to the present invention, measuring person prior to instruction of execution start of repeated continuous measurements, enter all one or a plurality of basic measurement conditions are likely to or used to use during the repeated continuous measurements Keep it. Where "might use" was the basic measurement conditions, if the measurement conditions change condition is dependent on the measured value, always measured conditions change condition depending on the situation of the measurement results are met This is because the basic measurement conditions input in advance may not be used as a result.

The information collection means collects information necessary for executing data processing corresponding to measurement under one or more basic measurement conditions input by the input means before the repeated continuous measurement is executed. Save in storage means. Here, “information necessary when executing data processing” is, for example, dark current data or baseline data, and in order to acquire such data, measurement is actually performed by operating each part of the spectrophotometer. There is a need to. Further, as the information, for example, there is a horizontal axis conversion table for data conversion in accordance with the set wavelength range and the wavelength interval when the horizontal axis represents the wavelength axis, these tables in accordance with a predetermined algorithm It can be obtained by calculation processing. Collection of such information requires a certain amount of time. However, such processing is performed during continuous measurement by ending all such processing and storing only the information in the storage means before execution of repeated continuous measurement. Can be eliminated.

  That is, the measurement control means executes measurement while changing the setting of the basic measurement condition as necessary based on a predetermined measurement condition change condition during repeated continuous measurement, and acquires measurement value data for each measurement. . The data processing means reads out information corresponding to the measurement under the basic measurement conditions set by the measurement control means from the storage means, and uses the information for the data obtained by each measurement. Execute the process. Since all information necessary for this data processing is stored in the storage means, even when the basic measurement conditions are changed, the time required for preparing the information is short enough to be ignored.

Note that the spectrophotometer according to the present invention is particularly useful for obtaining spectral data in a predetermined wavelength range in a short time. It is preferable that the spectrophotometer detects the chromatic dispersion light with a PDA detector, and the basic measurement condition is the charge accumulation time of the PDA detector.

  According to the spectrophotometer according to the present invention, it is possible to change basic measurement conditions such as the charge accumulation time of the PDA detector during the repeated measurement without increasing the measurement time interval of the repeated measurement. . Thus, for example, the charge accumulation time can be switched with the shortest dead time so that it can follow a rapid change in the sample during continuous measurement, and the state of the rapid change in time can be observed more precisely. According to the position (for example, detected by a position sensor) and the operation state of the external device, it is possible to switch to a short charge accumulation time as appropriate and observe more precisely. Further, in continuous monitoring of a liquid sample by a flow cell or transmission measurement or reflection measurement of a long sheet-like object, measurement can be performed in real time with an optimal measurement frequency according to a change in the sample.

Further, when changing the basic measurement conditions in the course of repeated measurements as described above, since the automatic basic measurement conditions in accordance with the measurement conditions change condition that has been decided Me pre is the measurement is changed is performed, the measurer Appropriate continuous measurement can be performed without any trouble.

  In addition, the amount of data can be appropriately reduced by changing the basic measurement conditions, so the total amount of data obtained in the entire repeated measurement can be suppressed, the data memory can be used efficiently, and the memory capacity can be reduced. This makes it possible to reduce costs. In addition, if the amount of data is large, the load on the processor that controls the reading and writing of data may increase, or the communication amount of command and data per unit time may increase, resulting in a decrease in system responsiveness. However, reducing the amount of data itself can alleviate these concerns.

  Furthermore, when the present invention is applied to a product inspection system that performs measurement while automatically exchanging different types of samples, it is not necessary to perform a baseline measurement every time the sample changes, thereby improving inspection throughput. There is an advantage.

  An ultraviolet-visible PDA spectrophotometer according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part of the spectrophotometer of the present embodiment, and FIGS. 2 and 3 are flowcharts for explaining characteristic control operations of the spectrophotometer of the present embodiment.

  A photometric unit 1 that performs absorption measurement on a sample includes a deuterium lamp 11, a halogen lamp 12, an optical path switching unit 13 for switching the light beams of both lamps, a sample cell 14 in which a sample solution is stored, A spectroscope 15 including a diffraction grating and the like, and a PDA detector 16 are included. As a basic operation, one of the emitted light from the deuterium lamp 11 or the emitted light from the halogen lamp 12 is selected by the optical path switching unit 13 and irradiated to the sample cell 14 as measurement light. When light passes through the sample solution accommodated in the sample cell 14, light having a wavelength characteristic to the component contained therein is absorbed. The transmitted light that has been absorbed is wavelength-dispersed by the spectroscope 15, and the spread wavelength-dispersed light enters the PDA detector 16 and is detected almost simultaneously.

  The PDA detector 16 includes a large number (for example, 512) of light receiving elements each having a configuration in which a photoelectric conversion photodiode and a charge storage capacitor are connected in parallel, and are arranged in a line on a silicon substrate. It is. In one light receiving element, light incident on the photodiode is converted into a charge signal and accumulated in a capacitor during a period in which the read switch is off. When the read switch is turned on, the charge accumulated in the capacitor is reduced. It is converted into a current signal or a voltage signal and output. Therefore, even if the light intensity is weak, a minute change can be clearly captured by lengthening the charge accumulation time, that is, the period in which the readout switch is off. On the other hand, if the incident light intensity is high, the charge is saturated and the output does not reflect the incident light intensity. For this reason, the charge accumulation time is very important for accurate measurement.

  The detection signal from the PDA detector 16 is digitized by the A / D converter 2 and sent to the data processor 3. The data processing unit 3 calculates the absorbance for each wavelength, for example, based on the collected detection data, creates an absorbance spectrum, or executes qualitative analysis or quantitative analysis. In such data processing, reference data described later stored in the reference data storage unit 31 is used. An input unit 5 and a display unit 6 are connected to the control unit 4 and have a function of controlling operations of the photometry unit 1 and the data processing unit 3. The control unit 4 includes a basic measurement condition storage unit 41 for storing basic measurement conditions set from the input unit 5, and performs control based on the basic measurement conditions stored therein.

  It should be noted that the data processing unit 3 and the control unit 4 can be configured in different forms depending on the change speed of the measurement target, the usage, and the like. For example, the measurement time interval is about the same as the charge accumulation time which is the minimum measurement repetition period of the PDA detector 16, and there is almost no delay in response to measurement data transmission / processing operation and measurement control operation (specifically, For observation of high-speed reaction, etc.), the data processing unit 3 and the control unit 4 may be configured by an MPU built in the spectrophotometer body and an MPU control program written in a ROM or the like. Further, when the measurement time interval is sufficiently large as compared with the charge accumulation time of the PDA detector 16 and a certain degree of response delay is allowed in measurement data transmission / processing operation and measurement control operation (specifically, The data processing unit 3 and the control unit 4 can be configured by a personal computer and a predetermined control program for the personal computer. Furthermore, when importance is placed on the operability of the measurer, the input unit 5 and the display unit 6 may be configured by a personal computer and a predetermined control program for the personal computer.

  Next, the control / processing operation at the time of repeated continuous measurement, which is a feature of the spectrophotometer of the present embodiment, will be described.

  Before repeated continuous measurement, the measurer changes the measurement conditions for switching the basic measurement conditions and the basic measurement conditions to be used or possibly used in the process of executing the sample measurement sequence in advance. Conditions are input and set from the input unit 5 (step S1). Here, basic measurement conditions include, for example, time axis parameters (charge accumulation time of PDA detector 16, data output time interval, number of data integrations, etc.), horizontal axis parameters (horizontal axis units (either normal wavelength or wave number), Horizontal axis range, horizontal axis interval, etc.). The measurement condition changing condition can be determined according to the sample measurement sequence, which will be described later in detail. The basic measurement conditions may be set so that a desired one can be selected from the measurement conditions stored in the spectrophotometer in advance, or the measurer can input a numerical value from the input unit 5. Also good. The contents input and set as described above are stored in the basic measurement condition storage unit 41.

  The measurer gives an instruction to start processing after setting the above items (step S2). When receiving this instruction, the control unit 4 collects the basic measurement conditions defined in the sample measurement sequence from the basic measurement condition storage unit 41 and obtains the total number N of basic measurement conditions (step S3). Then, the variable n is set to 1 (step S4), and it is determined whether or not n is larger than the total number N of basic measurement conditions (step S5). In this way, reference data is obtained.

  First, for the nth basic measurement condition p [n], the horizontal axis conversion table T [n] is calculated from the horizontal axis parameters (step S6). The horizontal axis conversion table T [n] is used to calculate the horizontal axis information (scale) of the spectrum, and is adjacent to the range of elements to be used among the detection signals of the respective elements obtained by the PDA detector 16. An integration range of detection signals of one or more elements is determined. Thereafter, the basic measurement condition p [n] is set as an actual measurement condition, and the photometry unit 1 is controlled to execute dark current measurement under the measurement condition. Then, the dark current signal of the PDA detector 16 is detected and used as dark current data D [n] (step S7). Next, under the same measurement conditions, a background measurement is performed in a state where no sample exists in the sample cell 14 (for example, only a solvent is filled), and a baseline serving as a spectrum baseline is obtained by this background measurement. Data B [n] is obtained (step S8).

  When the reference data for the basic measurement condition p [n] is obtained after completing these measurements, the reference data is transferred to the data processing unit 3, and the reference data is stored in association with the basic measurement condition or information for identifying the basic measurement condition. The data is stored in the unit 31 (step S9). Then, the variable n is incremented (step S10), and the process returns to step S5 to determine whether n is larger than N. If n is less than or equal to N, the process proceeds to steps S6 to S9 as described above, and the horizontal axis conversion table, dark current data D [n] and base under the incremented nth basic measurement condition p [n] Line data B [n] is obtained. Thus, when n is sequentially incremented and n> N, it is determined Yes in step S5, and this reference data collection process is terminated. In this way, until n reaches 1 to N, reference data for each basic measurement condition is collected and stored in the reference data storage unit 31 of the data processing unit 3.

  As described above, the spectrophotometer of the present embodiment collects all reference data regarding basic measurement conditions that can be used for continuous measurement prior to actual continuous measurement. The calculation processing and measurement operation for obtaining the reference data are not necessary, and the data stored in the reference data storage unit 31 is simply read out.

The following three measurement condition changing conditions for switching the basic measurement conditions can be considered.
(1) Number / time evaluation method (2) Photometric value evaluation method (3) External signal trigger method
Here , (1) the case of switching the basic measurement conditions by the number / time evaluation method, which is not included in the present invention, will be described, and then (2) the photometric value evaluation method employed in the present invention will be described.

  In the number / time evaluation method, the basic measurement conditions are changed for each predetermined number of acquired data or for each time. That is, unlike the photometric value evaluation method described later, the change of the basic measurement condition is not affected at all by the measurement result. FIG. 4 shows an outline of the measurement timing in the spectrophotometer of this example according to this method. In this example, the control unit 4 receives an external input signal that is substantially periodic (interval of time t0) (see (a)), and repeats N consecutive measurements from the time when the external input signal is delayed by a predetermined time t1. Is executed (see (b)). Such measurement is performed on a sample such as a product or an agricultural product that sequentially passes at a constant speed by a conveying unit such as a belt conveyor, with the aim of the timing at which the sample passes a position irradiated with measurement light. The case where repeated measurement is performed is assumed. In such an inspection system, a detection signal of a position sensor that detects the position of the sample can be used as an external input signal.

  After the measurement person gives an instruction to start continuous measurement, when the control unit 4 detects an external input signal, the control unit 4 counts a predetermined delay time t1 from that point, and repeats measurement when the delay time t1 elapses. That is, the control unit 4 sets the variable n to 1 (step S12), reads the nth basic measurement condition p [n] from the basic measurement condition storage unit 41 according to the set measurement sequence, and sets it as the measurement condition. (Step S13). Next, it is determined whether or not there is an instruction to complete or stop the measurement (step S14). If there is no measurement, the photometric unit 1 performs spectroscopic measurement on the sample (step S15) until desired measurement data is acquired. If measurement data is obtained by repeating the processes of steps S14 and 15 (Yes in step S16), the process proceeds to step S17.

  The data processing unit 3 reads the reference data corresponding to the basic measurement conditions at that time from the reference data storage unit 31 (step S17), and performs vertical axis and horizontal axis conversion for spectrum display using the reference data (step S17). Step S18). Such processing is the same as the conventional processing. Then, an index value such as absorbance is calculated from the measurement data obtained by the measurement, and a spectrum indicating the relationship between the wavelength or wave number and the signal intensity is obtained in accordance with the vertical axis and the horizontal axis (step S19) and stored. At the same time, it is output as a graph on the screen of the display unit 6 (step S20). Then, the variable n is incremented (step S21), and it is determined whether n is larger than N (step S22). If n is equal to or smaller than N, the process returns to step S13 and S13 is incremented for n. The subsequent processing is repeated.

  In this way, for each measurement from n = 1 to n = N, measurement can be performed under basic measurement conditions set in advance, and the basic measurement conditions are switched for each measurement. Even in this case, only the reference data is read out from the storage unit 31, so that the next measurement is not delayed.

Next, the photometric value evaluation method employed in the present invention will be described. In this method, an evaluation function for evaluating the measurement result is determined in advance, an evaluation value is calculated based on the evaluation function during the continuous measurement, the evaluation value is determined, and basic measurement is performed according to the determination result. Execute condition switching. The evaluation function can be a variety of functions such as linear, quadratic, higher-order, higher-order, higher-order, higher-order, third-order or higher-order, variable expression, integral, etc. The value itself may be used. In general, the evaluation function should be incorporated as a standard function in the application software for achieving the control operation. However, in some cases, it is desirable to use a function or formula other than the standard function. In some cases, it is preferable that the measurer can add and set an evaluation function that the measurer lacks appropriately later.

  When changing the basic measurement conditions by the photometric value evaluation method, the measurer inputs the evaluation function to be used and parameters such as coefficients necessary for determining the function from the input unit 5 before starting the measurement. . As for the evaluation function, it is only necessary to be able to select an appropriate one from a plurality of evaluation functions, and when there is no appropriate evaluation function among them, the measurer himself inputs and sets the function as described above. What should I do? Upon receiving an instruction to start continuous measurement, the control unit 4 sets initial basic measurement conditions for the photometry unit 1 and the data processing unit 3 and starts measurement. For each measurement, the data processing unit 3 reads the detection data digitized by the A / D conversion unit 2, calculates the absorbance for each wavelength based on the detection data, and obtains the absorbance spectrum. In addition, when an evaluation value is calculated from the data using a predetermined evaluation function and it is determined that the basic measurement condition needs to be changed based on the evaluation value, the basic measurement condition is obtained from the reference data storage unit 31. The data corresponding to is read and an instruction to change is given to the control unit 4.

  Specifically, when the time change of the absorbance at a certain wavelength is slow, the sensitivity is increased by increasing the charge accumulation time, while the time interval is widened, and when the absorbance changes abruptly, the charge accumulation time is shortened. By doing so, it is possible to narrow the time interval and make it easy to catch a sudden change state. In this method, the basic measurement conditions that are determined in advance in association with the evaluation value or the determination result of the evaluation value are not always used.

Next, an external signal trigger method not included in the present invention will be described. In this method, basic measurement conditions to be used are described in advance in the order of use, and when an external trigger signal for instructing basic measurement condition change is input from an external device (not shown) or the input unit 5 to the control unit 4, The basic measurement conditions are sequentially changed for each input of the signal. A measurement condition change reset signal is also provided, and when this measurement condition change reset signal is input, it is preferable to return to the first basic measurement condition regardless of the immediately preceding basic measurement condition.

  The above description is only an example of the present invention, and various modifications can be considered. In the following, some possible modifications will be described.

  Since a certain amount of time is required to repeat dark current measurement and background measurement in the reference data processing described above, the number of times of dark current measurement and background measurement should be reduced as much as possible to shorten the measurement time. It is preferable to reduce. In order to reduce hardware costs, it is preferable to suppress the storage capacity of the reference data storage unit 31. Therefore, for example, when the same basic measurement conditions exist in p [n] (where n = 1 to N), the actual measurement operation is performed once (one for each of the dark current measurement and the background measurement). The reference data stored in the reference data storage unit 31 during processing such as data correction, which will be described later, is used in common, or the same data is simply used when data is written into the reference data storage unit 31. Or copy it.

  In p [n] (where n = 1 to N), dark current measurement and background measurement under a plurality of basic measurement conditions are not under the same basic measurement condition. Can be represented by the result of dark current measurement or background measurement, measurement under conditions other than the representative basic measurement conditions can be omitted. Specifically, for example, when the charge accumulation time and the horizontal axis parameters are the same and only the average number of times of the results is different, the number of times of accumulation is higher as data (higher accuracy, higher sensitivity, etc.). The more conditions should be adopted for actual measurement. The same applies when the result of dark current measurement or background measurement under another basic measurement condition can be calculated from the result of dark current measurement or background measurement under one basic measurement condition. In addition, dark current measurement and background measurement can be omitted. For example, if the time axis parameters are the same, only the horizontal axis range is different among the basic measurement conditions, and one horizontal axis range includes all other horizontal axis ranges, the conditions with a wide horizontal axis range are actually used. It is sufficient to extract the data with the narrower horizontal axis range from the data with the wider horizontal axis range. In addition, when only the horizontal axis interval is different among the basic measurement conditions, the condition with the small horizontal axis interval is adopted for actual measurement, and the horizontal axis is reduced by data processing such as thinning out from the data with the smaller horizontal axis interval. Data with a larger interval may be generated.

  Further, in the control / processing operation of the spectrophotometer of the above embodiment, it is assumed that a reference sample (blank sample) is automatically set in a state where a measurement start instruction is received and such a reference is set. There may be cases where the state cannot be realized automatically, or even if it can be realized, it takes too much time to be practical. When the measurement system is stable and the basic measurement conditions are determined, the photometric value in the reference state is almost constant (that is, the reproducibility is high). When the state of the sample can be estimated from different horizontal axis values on the same spectrum (for example, relative values of intensity corresponding to wavelength values), various basics can be used at appropriate times, such as during installation or periodic inspection. The dark current data and the baseline data for the measurement conditions may be acquired together, and a reference data database that can be searched using the basic measurement conditions as a key may be created.

In the photometric value evaluation method and the external signal trigger method, basically, the source of the switching signal of the basic measurement conditions are asynchronous to the measurement operation by the photometry section, of the basic measurement conditions in the next measurement of a certain measurement The change is not necessarily realized before the start of the next charge accumulation operation. For example, when an external signal for changing the basic measurement conditions is input during the charge accumulation of the PDA detector 16, a read operation is performed immediately to discharge all the accumulated charges at that time, and then the change is made. A method of setting a new parameter later is also conceivable, but if this is done, the data being measured (data based on the charge being accumulated) is wasted.

In order to avoid such waste, either of the following two methods can be employed.
(1) For example, data based on the charge that is being stored at the time when the external instruction signal is input is executed immediately before that, that is, until reading according to the basic measurement conditions (charge storage time) before the change, and after the change is completed Set new basic measurement conditions.
(2) For example, when an external instruction signal is input, it is determined whether or not the change of the basic measurement condition is in time for reading the data based on the charge that is being stored at that time. When it is not in time, the process (1) is executed.

However, in the method (1), there is a maximum delay of one charge accumulation time immediately before the change of the charge accumulation time. On the other hand, the method (2) can be realized by the following procedure, for example. That is, when the charge accumulation time is managed by a hardware timer, the remaining count up to the timer count-up is read at the time of external signal input, the remaining count value C1 at that time, the changed count value C2, and the change Regarding the previous count value C3 and the remaining count value C4 after the change,
C4 ≡ C1 + (C2−C3) ≧ 0
It is examined whether or not. If the above condition is satisfied, it is determined that the charge accumulation time can be changed from the data based on the charge being accumulated at that time, and the new count value C4 after the change is immediately set in the timer. On the other hand, if the above condition is not satisfied, the process waits until the data reading at that time is completed, and then sets the new count value C4 after the change in the timer.

  In the photometric value evaluation method, when the charge accumulation time is much shorter than the data reading time from the PDA detector + the processing time of the measurement data + the data transmission time, the time when the data reading from the PDA detector 16 is started Then, the evaluation for the previous data is not finished yet. Therefore, the change of the charge accumulation time should be postponed at least once. In addition, when the time required for the evaluation calculation is dominant in the entire processing time, the evaluation frequency is set so that the evaluation is performed only once every several times instead of performing the evaluation for each measurement. Preferably, it is reduced or the evaluation algorithm is simplified. On the other hand, if the time required for horizontal axis conversion or data transmission is dominant in the overall processing time, the number of measurement points per measurement (data, such as narrowing the horizontal axis range or widening the horizontal axis interval) It is better to perform processing that reduces the number).

  Further, the dark current measurement and background measurement start timings may be executed in the same sequence as the sample measurement start timing, but they are not necessarily the same. For example, even in a system configured to perform sample measurement by an external signal trigger coming from a predetermined external device, the dark current measurement and the background measurement may use a key operation from the input unit 5 as a measurement start instruction. Thus, the reference data can be acquired in a state where the system is guaranteed to be stable.

  Further, in the switching of the basic measurement conditions by the photometric value evaluation method or the external signal trigger method, the control unit 4 does not grasp the timing of the switching in advance, and the time and the time of the switching are used even when trying to verify later. The basic measurement conditions may be unknown. Therefore, the actual measurement time, the contents of the basic measurement conditions, and the like may be recorded in the header portion of the measurement data acquired by each measurement.

  In addition, it is obvious that points other than those described above are also included in the scope of the claims of the present application even if appropriate modifications, corrections, additions, etc. are made within the scope of the present invention.

The block diagram of the principal part of one Example of the spectrophotometer which concerns on this invention. The flowchart for demonstrating the characteristic control / processing operation | movement in the spectrophotometer of a present Example. The flowchart for demonstrating the characteristic control / processing operation | movement in the spectrophotometer of a present Example. The schematic waveform diagram for demonstrating an example of control operation of the spectrophotometer of a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Photometry part 11 ... Deuterium lamp 12 ... Halogen lamp 13 ... Optical path switching part 14 ... Sample cell 15 ... Spectrometer 16 ... PDA detector 2 ... A / D conversion part 3 ... Data processing part 31 ... Reference data storage part 4 ... Control unit 41 ... Basic measurement condition storage unit 5 ... Input unit 6 ... Display unit

Claims (2)

In a spectrophotometer that performs continuous measurement multiple times for the same or multiple samples,
a) At least one basic measurement condition of the charge accumulation time of the photodiode array detector, the number of data integrations, or the parameter on the horizontal axis of the spectrum is used or may be used at the time of each spectrum measurement in repeated continuous measurement. An input means for a measurer to input a plurality of certain values;
b) Information necessary for executing data processing corresponding to spectrum measurement under a plurality of types of values for at least one basic measurement condition input by the input means, before the repeated continuous measurement is executed. In addition, information collecting means for collecting each of the plurality of types of values and storing them in the reference data storage means,
c) Evaluation function storage means for storing a predetermined evaluation function for judging a specific fluctuation state of the measurement value with respect to time,
d) evaluation value calculation means for calculating an evaluation value from the measurement value using the evaluation function stored in the evaluation function storage means for each measurement during the execution of repeated continuous measurement;
e) While performing the repeated continuous measurement, while changing the set value of the basic measurement condition using the evaluation value calculated by the evaluation value calculating means or the judgment result of the evaluation value in light of a predetermined reference as the measurement condition changing condition Measurement control means for performing spectrum measurement;
f) The information corresponding to the spectrum measurement under the set value of the basic measurement condition set by the measurement control means is read from the reference data storage means, and the data acquired by each spectrum measurement is read Data processing means for executing data processing using the information,
A spectrophotometer comprising:
A spectrophotometer that wavelength-disperses light transmitted or reflected from a sample and detects the wavelength-dispersed light by a photodiode array detector, wherein the basic measurement condition is a charge accumulation time of the photodiode array detector The spectrophotometer according to claim 1 .

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