Test Equipment

Abstract

To test a measuring instrument such as a multichannel analyzer for counting an input pulse signal.SOLUTION: A test device includes: a plurality of pulse generators each generating a pulse signal at different frequencies; a plurality of pulse signal counters each being provided corresponding to each of the plurality of pulse generators; a count aggregation unit for aggregating a count value counted by respective plurality of pulse signal counters; a pulse synthesizer for generating an input pulse signal by synthesizing a pulse signal generated by respective plurality of pulse generators; and a control unit for synchronizing a start and an end of counting of the pulse signals performed by a plurality of pulse signal counters with the start and the end of counting of the pulse signals performed by a measuring instrument.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a test device. [Background technology]

[0002] In a conventional radioactivity measuring device, a multi-channel analyzer calculates count values ​​for each of a plurality of channels set according to pulse height values ​​for a pulse signal output from a radiation detector. For example, when a pulse signal having a pulse height value corresponding to the energy of radiation is output from the radiation detector, the multi-channel analyzer creates an energy spectrum as a pulse height distribution of the pulse signal output from the radiation detector.

[0003] Generally, a multi-channel analyzer has a dead time between the detection of a pulse signal and the detection of the next pulse signal (see, for example, Non-Patent Document 1). For this reason, a multi-channel analyzer has a live time correction function that corrects the effective measurement time (live time) by taking into account the dead time during measurement (see, for example, Patent Document 1). Also, a Poisson pulse train generator described in Non-Patent Document 2, for example, is known as a random pulse signal generator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-80576 [Non-patent literature]

[0005] [Non-Patent Document 1] "Radioactivity Measurement Method Series No. 7: Gamma-ray Spectrometry Using Germanium Semiconductor Detectors," Nuclear Regulation Authority, Monitoring and Information Division, September 2020 [Non-patent document 2] Takami Koyanagi, Shinichi Nakajima, Shigeru Yamada, "Poisson Pulse Train Generator," Transactions of the Society of Instrument and Control Engineers, Vol. 17, No. 7, June 1981 Summary of the Invention [Problem to be solved by the invention]

[0006] One possible method for testing the dead time of a multi-channel analyzer is to input a test pulse signal, which is a combination of periodically generated periodic pulse signals and randomly generated random pulse signals, or a test pulse signal consisting solely of random pulse signals, into the multi-channel analyzer and compare the count value of the multi-channel analyzer with the number of input test pulse signals over the actual measurement time (real time). Methods for obtaining such random pulse signals include the method described in Non-Patent Document 2 and a method using actual radioisotopes (RIs). However, the method described in Non-Patent Document 2 has a lower limit on the interval between generated pulse signals, and the interval between pulse signals does not become zero, making it impossible to generate multiple pulse signals that overlap in time. Furthermore, the method using radioisotopes makes it difficult to accurately count the number of pulse signals generated by the radioisotopes.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a test apparatus capable of testing measuring instruments such as multi-channel analyzers that count input pulse signals. [Means for solving the problem]

[0008] One aspect of the present invention is a test apparatus for testing a measuring instrument that counts input pulse signals, the test apparatus comprising: a plurality of pulse generators that each generate pulse signals at a different frequency; a plurality of pulse signal counters provided corresponding to each of the plurality of pulse generators; a counting and tallying unit that tally the count values ​​counted by each of the plurality of pulse signal counters; a pulse synthesizer that generates the input pulse signal by synthesizing the pulse signals generated by each of the plurality of pulse generators; and a control unit that synchronizes the start and end of counting pulse signals performed by the plurality of pulse signal counters with the start and end of counting pulse signals performed by the measuring instrument. One aspect of the present invention is a test device as described above, further comprising an output unit that outputs data indicating the relationship between an actual count rate calculated from the actual measurement time from the start to the end of counting the pulse signal and the count value of the counting and counting unit, and a measured count rate calculated from the corrected measurement time in which the dead time of the measuring device has been corrected and the count value of the measuring device. [Effects of the Invention]

[0009] According to the present invention, it is possible to obtain an effect that it is possible to test a measuring instrument such as a multi-channel analyzer that counts input pulse signals. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a configuration diagram of a test device according to an embodiment of the present invention; [Figure 2] 1 is a flowchart showing the procedure of a testing method according to an embodiment of the present invention. [Figure 3] FIG. 10 is a graph showing an example of test results according to an embodiment of the present invention. [Figure 4] FIG. 1 is a configuration diagram showing a first modified example of a test device according to an embodiment of the present invention. [Figure 5] FIG. 10 is a configuration diagram showing a second modified example of the test device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] A testing device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the test apparatus 1 according to this embodiment includes a plurality (n) of pulse generators 2 (2-1, 2-2, . . . , 2-n, where n is an integer equal to or greater than 2), a plurality (n) of pulse signal counters 3 (3-1, 3-2, . . . , 3-n) provided corresponding to each of the plurality (n) of pulse generators 2, a pulse synthesizer 4, a counting and tallying unit 5, a control unit 6, an output unit 7, and an input unit 8.

[0012] The test apparatus 1 is a test apparatus for testing a measuring instrument that counts input pulse signals. In FIG. 1, a multi-channel analyzer (MCA) 100 is connected to the test apparatus 1 as an example of a measuring instrument that counts input pulse signals. The test apparatus 1 inputs an input pulse signal B to the multi-channel analyzer 100. The multi-channel analyzer 100 counts the input pulse signal B and outputs measurement information H based on the counting result. The multi-channel analyzer 100 starts and stops counting the input pulse signal B in accordance with a measurement control signal E output from the test apparatus 1.

[0013] In the test apparatus 1, a pulse generator 2 generates a pulse signal A at a frequency f. The pulse signal A generated by the pulse generator 2 is input to a corresponding pulse signal counter 3. For example, a pulse generator 2-1 generates a pulse signal A-1 at a frequency f1. The pulse signal A-1 generated by the pulse generator 2-1 is input to a pulse signal counter 3-1. For example, a pulse generator 2-2 generates a pulse signal A-2 at a frequency f2. The pulse signal A-2 generated by the pulse generator 2-2 is input to a pulse signal counter 3-2. For example, a pulse generator 2-n generates a pulse signal An at a frequency fn. The pulse signal An generated by the pulse generator 2-n is input to a pulse signal counter 3-n.

[0014] The frequencies f1, f2, . . . , fn of the pulse signals A-1, A-2, . . . , An generated by the multiple (n) pulse generators 2-1, 2-2, . . . , 2-n are set in advance. The frequencies f1, f2, . . . , fn may be fixed or may vary for each test. For example, multiple tests with different frequencies f1, f2, . . . , fn may be performed on the same multi-channel analyzer 100. The frequency f may be any interval such that the number of pulse signals A per unit time is constant and the intervals between the pulse signals A are random.

[0015] The pulse signal counter 3 counts the pulse signals A generated by the pulse generator 2 and outputs a count value C. For example, the pulse signal counter 3-1 counts the pulse signals A-1 generated by the pulse generator 2-1 and outputs a count value C-1. For example, the pulse signal counter 3-2 counts the pulse signals A-2 generated by the pulse generator 2-2 and outputs a count value C-2. For example, the pulse signal counter 3-n counts the pulse signals An generated by the pulse generator 2-n and outputs a count value Cn.

[0016] The pulse signal counter 3 starts, stops, and resets counting of pulse signal A in accordance with the measurement control signal E output from the control unit 6. For example, the pulse signal counter 3-1 starts, stops, and resets counting of pulse signal A-1 in accordance with the measurement control signal E. For example, the pulse signal counter 3-2 starts, stops, and resets counting of pulse signal A-2 in accordance with the measurement control signal E. For example, the pulse signal counter 3-n starts, stops, and resets counting of pulse signal An in accordance with the measurement control signal E.

[0017] The counting and tallying unit 5 tallies the count values ​​C-1, C-2, ..., Cn counted by the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n, respectively, and outputs the tallied value D. The tallied value D is, for example, the total value obtained by adding up the count values ​​C-1, C-2, ..., Cn. When an output control signal G output from the control unit 6 commands initialization, the counting and tallying unit 5 clears the tallied value D.

[0018] The pulse synthesizer 4 generates an input pulse signal B by synthesizing pulse signals A-1, A-2, . . . , An generated by multiple (n) pulse generators 2-1, 2-2, . . . , 2-n. The input pulse signal B is, for example, a single waveform signal resulting from adding together the pulse signals A-1, A-2, . . . , An. The input pulse signal B generated by the pulse synthesizer 4 is output from the test apparatus 1 and input to the multi-channel analyzer 100. In addition, the pulse synthesizer 4 may delete pulse signals generated as a result of adding together two or more pulse signals A that overlap in time, so that they are not included in the input pulse signal B (so that they are not input to the multi-channel analyzer 100).

[0019] The control unit 6 controls the tests performed by the test apparatus 1. An instruction signal J is input to the control unit 6 from an input unit 8 operated by an operator. The instruction signal J is a signal that instructs, for example, starting or stopping a test, presetting the actual measurement time, or clearing a test. The control unit 6 outputs a measurement control signal E based on the instruction signal J. The measurement control signal E is a signal for synchronizing the start and end of counting pulse signals performed by the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n with the start and end of counting pulse signals performed by the multi-channel analyzer 100. The same measurement control signal E is input to the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100. As a result, the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100 start counting pulse signals when the measurement control signal E indicates the start of counting pulse signals. Furthermore, the plurality of (n) pulse signal counters 3-1, 3-2, . . . , 3-n and the multi-channel analyzer 100 end counting the pulse signals when the measurement control signal E indicates the end of counting the pulse signals.

[0020] The control unit 6 is equipped with a timer TIM. The timer TIM measures the actual measurement time. The control unit 6 sets the actual measurement time specified by the instruction signal J in the timer TIM. When the instruction signal J instructs the control unit 6 to start a test, the control unit 6 starts measuring time in the timer TIM and simultaneously instructs the timer 6 to start counting pulse signals using a measurement control signal E. When the timer TIM has completed measuring the actual measurement time, the control unit 6 instructs the timer 6 to stop counting pulse signals using the measurement control signal E.

[0021] For example, when timer TIM starts timing the actual measurement time, the measurement control signal E opens the input gate of each pulse signal A-1, A-2, ..., An to each pulse signal counter 3-1, 3-2, ..., 3-n. Also, when timer TIM completes timing the actual measurement time, the measurement control signal E closes the input gate of each pulse signal A-1, A-2, ..., An to each pulse signal counter 3-1, 3-2, ..., 3-n. Note that when the instruction signal J indicates the pulse generator 2 (frequency f) to be used for the test, the control unit 6 uses the measurement control signal E to open the input gate of the pulse signal A only for the pulse signal counter 3 corresponding to the pulse generator 2 (frequency f) to be used for the test.

[0022] Furthermore, the control unit 6 forcibly ends the test when an instruction to stop the test is given by the instruction signal J. Furthermore, the control unit 6 resets the test device 1 when an instruction to clear the test is given by the instruction signal J.

[0023] The output unit 7 outputs the test results. The test results are, for example, the count value D output from the counting and collection unit 5, or data based on the count value D and the measurement information H of the multi-channel analyzer 100. The output unit 7 outputs the test results in accordance with the output control signal G output from the control unit 6. The control unit 6 uses the output control signal G to instruct the output unit 7 to initialize when the test starts. This causes the output unit 7 to initialize the test results (clear data, etc.). The control unit 6 uses the output control signal G to instruct the output unit 7 to output the test results when the test ends. The control unit 6 uses the output control signal G to instruct the output unit 7 to output the test results, for example, when the measurement of the actual measurement time has completed or when the test is forcibly terminated. This causes the output unit 7 to output the test results.

[0024] The output unit 7 calculates, for example, the actual counting rate (ICR). The ICR is a quotient obtained by dividing the counted value D of the counting and counting unit 5 by the actual measurement time (real time). The output unit 7 calculates the ICR by dividing the counted value D of the counting and counting unit 5 by the actual measurement time. The actual measurement time is notified to the output unit 7 from the control unit 6 by an output control signal G.

[0025] The output unit 7 outputs, for example, data indicating the relationship between ICR and OCR as the test result. The OCR is the quotient obtained by dividing the count value of the input pulse signal B, which is the result of counting by the multi-channel analyzer 100, by the corrected measurement time (live time) obtained by correcting the dead time using the live time correction function of the multi-channel analyzer 100. The multi-channel analyzer 100 outputs the OCR based on the count result of the input pulse signal B, including it in the measurement information H.

[0026] The output unit 7 may be configured to output information indicating the following output contents. (Output contents) · Counting and counting unit 5 outputs count value D · Individual count values ​​of each pulse signal counter C-1, C-2,..., Cn - The elapsed time measured by the timer TIM Counting rate obtained by dividing the count value output by the counting unit 5 or the count value of each pulse signal counter by the elapsed time of the timer TIM ·Frequency f1, f2, ···, fn of each pulse generator 2-1, 2-2, ···, 2-n The output unit 7 may also be provided with a display device, and the output information may be displayed on the display device.

[0027] In addition, a personal computer (not shown) may be connected to the test device 1 and the multi-channel analyzer 100, and the personal computer may be used to collect the counting and counting unit 5's aggregated values ​​D and the multi-channel analyzer 100's measurement information H, and analyze the collected data.

[0028] The operation of the test apparatus 1 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the procedure of the test method according to this embodiment. In the test apparatus 1, multiple (n) pulse generators 2-1, 2-2, ..., 2-n generate pulse signals A-1, A-2, ..., An at respective frequencies f1, f2, ..., fn. The frequencies f1, f2, ..., fn are set in advance so that multiple pulse signals are superimposed within a short period of time in the input pulse signal B. A method for determining the frequency f of pulse signal A (method for determining the pulse generation frequency) will be described later.

[0029] (Step S1) At the start of the test, the control unit 6 instructs the counting and tallying unit 5 and the output unit 7 to perform initialization using an output control signal G. This causes the counting and tallying unit 5 to clear the count value D, and the output unit 7 to initialize the test results (clear data, etc.).

[0030] (Step S2) The control unit 6 instructs the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100 to start counting pulse signals by using the measurement control signal E. This causes the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100 to start counting pulse signals.

[0031] (Step S3) The control unit 6 measures a predetermined measurement time, and when the measurement time has elapsed, the process proceeds to step S4.

[0032] (Step S4) The control unit 6 uses a measurement control signal E to instruct the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100 to end counting the pulse signals. This causes the multiple (n) pulse signal counters 3-1, 3-2, ..., 3-n and the multi-channel analyzer 100 to end counting the pulse signals. The multi-channel analyzer 100 outputs measurement information H based on the counting result of the input pulse signal B.

[0033] (Step S5) The counting and tallying unit 5 tally up the count values ​​C-1, C-2, . . . , Cn counted by the plurality (n pieces) of pulse signal counters 3-1, 3-2, . . . , 3-n, respectively, and outputs the tally value D.

[0034] (Step S6) The control unit 6 instructs the output unit 7 to output the test result using an output control signal G. This causes the output unit 7 to output the test result. For example, the output unit 7 outputs the counted value D of the counting and tabulating unit 5. For example, the output unit 7 outputs the test result based on the counted value D of the counting and tabulating unit 5 and the measurement information H of the multi-channel analyzer 100.

[0035] 3 is a graph showing an example of test results according to this embodiment, in which the horizontal axis represents the actual count rate (ICR) and the vertical axis represents the observed count rate (OCR).

[0036] ICR is the quotient obtained by dividing the counted value D of the counting and counting unit 5 by the actual measurement time (real time). The output unit 7 calculates ICR by dividing the counted value D of the counting and counting unit 5 by the actual measurement time. The control unit 6 notifies the output unit 7 of the predetermined measurement time measured in step S3 as the actual measurement time by using an output control signal G.

[0037] The OCR is the quotient obtained by dividing the count value of the input pulse signal B, which is the result of counting by the multichannel analyzer 100, by the corrected measurement time (live time) obtained by correcting the dead time using the live time correction function of the multichannel analyzer 100. The multichannel analyzer 100 outputs the OCR based on the count result of the input pulse signal B, including it in the measurement information H.

[0038] The output unit 7 generates a graph W showing the relationship between ICR and OCR and outputs it as the test result. The output unit 7 generates the graph W showing the relationship between ICR and OCR using the ICR and OCR obtained from multiple tests at different frequencies f1, f2, ..., fn performed on the same multi-channel analyzer 100. This graph W can be used to evaluate the OCR of the multi-channel analyzer 100, the performance of the dead time and live time correction function, etc.

[0039] [Variation 1] FIG. 4 is a configuration diagram showing a first modified example of the test apparatus 1 according to this embodiment. In FIG. 4, parts corresponding to those in FIG. 1 are given the same reference numerals, and their description will be omitted. In the test apparatus 1 of FIG. 1, the control unit 6 is provided with the timer TIM, but in the test apparatus 1a shown in FIG. 4, the counting and tallying unit 5a is provided with the timer TIM. The control unit 6a instructs the start of counting pulse signals by a measurement control signal E. When the measurement control signal E indicates the start of counting pulse signals, the counting and tallying unit 5a starts time measurement by the timer TIM. The actual measurement time to be set in the timer TIM is instructed in advance by the control unit 6a by the measurement control signal E. When the counting of the actual measurement time by the timer TIM is completed, the counting and tallying unit 5a calculates the count value D.

[0040] [Variation 2] FIG. 5 is a configuration diagram showing a second modification of the test apparatus 1 according to this embodiment. In FIG. 5, parts corresponding to those in FIG. 1 are assigned the same reference numerals, and their description will be omitted. The test apparatus 1 in FIG. 1 includes an input unit 8 that outputs an instruction signal J, whereas the test apparatus 1b shown in FIG. 5 has a multi-channel analyzer 100b that outputs an instruction signal Jb. Similar to the instruction signal J, the instruction signal Jb is a signal that instructs, for example, starting or stopping a test, presetting the actual measurement time, or clearing a test. The instruction signal Jb from the multi-channel analyzer 100b is input to the control unit 6b. The control unit 6b outputs a measurement control signal E based on the instruction signal Jb from the multi-channel analyzer 100b.

[0041] [How to determine the pulse generation frequency] Multiple (n) pulse generators 2-1, 2-2, . . . , 2-n generate pulse signals A-1, A-2, . . . , An at respective frequencies f1, f2, . . . , fn. The relationship between the frequencies f1, f2, . . . , fn is expressed by the following equation: f1=F, F is a constant. f2=f1+δ f3=f1+2δ f4=f1+3δ fn=f1+(n-1)δ

[0042] δ is expressed by the following formula. δ=k×P×F(Hz) P is the shortest "pulse signal interval (seconds) (time between two consecutive pulse signals)" (pulse pair resolution) that can be recognized by the measuring device (e.g., multi-channel analyzer 100) being tested. F may be arbitrarily determined within the range of "100 / n" Hz to "5 / n" MHz, for example. The value of k may be arbitrarily determined in accordance with the actual measurement time, for example, within the range of "1 / 100" to 100. For example, "k=1" may be used.

[0043] For example, when "P=1 μs" and "F=1000 Hz" and "k=1", then "δ=0.001 Hz". f1=1000Hz f2=1000.001Hz f3=1000.002Hz f4=1000.003Hz fn=1000Hz+(n-1)×0.001Hz This becomes:

[0044] As described above, according to this embodiment, it is possible to test a measuring instrument such as a multi-channel analyzer that counts input pulse signals.

[0045] Although the above-described embodiment tests a multi-channel analyzer, the present invention may be applied to testing of measuring instruments other than multi-channel analyzers. For example, the present invention may be applied to testing of measuring instruments that count multiple events as pulses of electrical signals (pulse signals), such as particle measuring instruments and foreign matter inspection devices.

[0046] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0047] 1, 1a, 1b... Test equipment, 2... Pulse generator, 3... Pulse signal counter, 4... Pulse synthesizer, 5... Counting and collecting section, 6, 6a, 6b... Control section, 7... Output section, 8... Input section

Claims

1. In a test apparatus for testing a measuring instrument that counts input pulse signals, a plurality of pulse generators each generating a pulse signal at a different frequency; a plurality of pulse signal counters provided corresponding to the plurality of pulse generators, respectively; a counting and tallying unit that tallies the count values ​​respectively counted by the plurality of pulse signal counters; a pulse synthesizer that generates the input pulse signal by synthesizing the pulse signals generated by the plurality of pulse generators; a control unit that synchronizes the start and end of counting pulse signals performed by the plurality of pulse signal counters with the start and end of counting pulse signals performed by the measuring device; A test device comprising:

2. an output unit that outputs data indicating the relationship between an actual count rate calculated from an actual measurement time from the start to the end of counting the pulse signal and the count value of the counting unit, and a measured count rate calculated from a corrected measurement time in which a dead time of the measuring device is corrected and the count value of the measuring device; The test device of claim 1 further comprising:

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