JP2008256380A - Optical measuring instrument and adjustment method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance measuring accuracy by reducing the individual differences among a plurality of photodetectors. <P>SOLUTION: In a delay emission measuring instrument 1 equipped with a plurality of delay emission detectors P, electrostatic voltage is applied so that the relative ratio of the rate of change of the ouput of the reference light which is inputted to the delay emission detectors P, and the rate of change of the output of the output value outputted from the delay emission detectors P becomes constant, within a predetermined range with the output value is corrected, so that the output characteristics in this state becomes approximate at a plurality of the delay emission detectors P. As a result, the dynamic ranges D of a plurality of the delay emission detectors P can be made to respectively correspond to the intensities of respective delay emissions. Furthermore, individual differences among a plurality of the delay emission measuring instruments 1 are reduced by correcting the output value, and measurement accuracy can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical measurement device that measures weak light such as delayed light emission of a photosynthetic sample, and a method for adjusting the optical measurement device.

For example, an optical measurement device (see Patent Document 1) for measuring a sample such as phytoplankton and an optical measurement device (see Patent Document 2) that measures delayed fluorescence emitted from a photosynthetic sample are known. However, in these apparatuses, it is not considered to simultaneously measure a plurality of samples with a plurality of detectors. On the other hand, for example, Patent Document 3 discloses an optical measurement device including a plurality of independent optical systems for simultaneously measuring a plurality of samples. This optical measuring device is provided with a plurality of independent photodiodes to simultaneously measure the amount of light transmitted to a plurality of samples, and further, measurement values generated by individual differences in sensitivity for each photodiode. In order to eliminate the variation, a correction unit for correcting the measurement data is provided.
JP 2004-101196 A International Publication No. 2005/062027 Pamphlet Japanese Patent Publication No. 6-19351

  However, since the device described in Patent Document 3 uses a photodiode that does not have a multiplication function, it is difficult to measure weak light such as delayed light emission. In addition, even when a photodetector using a photomultiplier tube is applied to a conventional optical measurement device, when measuring weak light, there is a large variation in measurement values due to individual differences in each photodetector. As a result, accurate measurement results could not be obtained.

  The present invention aims to solve the above problems, and provides an optical measurement device capable of calibrating individual differences among a plurality of photodetectors and improving measurement accuracy, and a calibration method for the optical measurement device. The purpose is to do.

  The present invention is an optical measurement device that detects light from a measurement target, and receives light and outputs light signals in response to an applied voltage, and the light intensity is different. The relative ratio between the light intensity change rates of at least three types of input light included in the predetermined light intensity range and the output change rates of the three types of output values output from the photodetector in response to input of the input light is predetermined. A storage unit that stores the applied voltage value set so as to be constant in the range of each of the plurality of photodetectors, and an output characteristic in a state where the applied voltage value is applied to the photodetector are And an arithmetic unit that corrects an output value so as to approximate a predetermined reference output characteristic.

  Photodetectors having a multiplication function have individual differences in sensitivity, and the light intensity ranges of input light that can be detected with the same voltage applied to each of the plurality of photodetectors are different. On the other hand, this light intensity range can be finely adjusted by adjusting the applied voltage due to the characteristics of the photodetector. In the present invention, the light intensity is different, and the relative ratio between the light intensity change rate based on at least three types of input light included in the predetermined light intensity range and the output change rate based on the corresponding three output values is predetermined. The applied voltage value is set so as to be constant within the range, and the applied voltage value is stored in association with each of the plurality of photodetectors. Therefore, an applied voltage value corresponding to the characteristics of the photodetector can be applied to each photodetector, and the characteristics of the output value for the input light of each photodetector in a predetermined light intensity range can be made constant. As a result, it is possible to accurately measure the light included in the predetermined light intensity range. In addition, since the output values of the plurality of photodetectors are corrected so as to approximate the reference output characteristics, individual differences among the plurality of photodetectors can be reduced, and measurement accuracy can be improved. .

  Furthermore, it is preferable that the relative ratio is set so as to approximate between a plurality of photodetectors. By approximating the relative ratio in a plurality of light detection periods, the inclination of the output characteristic with respect to the light input matches in each detection period. Therefore, it is possible to correct the output values for the input light having the same intensity so as to be substantially the same value, to reduce individual differences among the plurality of photodetectors, and to improve the measurement accuracy.

  Further, the storage unit associates correction constants set so that the output characteristics in a state where the applied voltage value is applied to the photodetectors are approximated by the plurality of photodetectors, to each of the plurality of photodetectors. Further, it is preferable that the calculation unit corrects the output values from the plurality of photodetectors based on the correction constant stored in the storage unit. Since the correction constant for correcting the output value is stored in the storage unit, the calculation unit can correct the output value based on the correction constant, and the measurement accuracy can be improved.

  Furthermore, it is preferable that the minimum value and the maximum value in the predetermined light intensity range are within the dynamic range of the photodetector. The dynamic range is the range between the minimum and maximum values of light intensity that can be detected by the photodetector. If the minimum and maximum values in a given light intensity range are within the dynamic range, the photodetector Thus, light within a predetermined light intensity range can be accurately detected.

Further, the three kinds of input light are output from the photodetector in accordance with the first light intensity L1, the second light intensity L2, the third light intensity L3, and the input light in order from the lowest. When the three types of output values are set as the first output value C1, the second output value C2, and the third output value C3 in order from the lowest,
The light intensity change rate is Log (La / Lb) (a = 1or2or3, b = 1or2or3, a ≠ b),
The output change rate is Log (Ca / Cb) (a = 1or2or3, b = 1or2or3, a ≠ b),
Preferably, the applied voltage value is set such that a relative ratio Nab between the light intensity change rate and the output change rate shown in the following formula A is constant within the predetermined range. is there.
Nab = {Log (Ca / Cb) / Log (La / Lb)}… (A)
In this way, by adjusting the applied voltage, the output characteristics with respect to the input light can be set to be constant within a predetermined range.

  Furthermore, the intensity of the three types of input light is the first intensity, the second intensity, and the third intensity in order from the lowest, and the three types of input light output from the photodetector by the input of each input light. The output values are a first output value, a second output value, and a third output value, and the applied voltage value is a first light intensity change rate obtained by dividing the second intensity by the first intensity, 2 is obtained by dividing the second output value by the first output value, the second light intensity change rate by dividing the third intensity by the second intensity, and the third output value by the first output value. It is preferable that the output characteristic relative to the input light is set to be constant within a predetermined range by approximating the relative ratio of the second output change rate divided by the output value of 2.

  The first unit further includes a plurality of measurement units each including a first unit to which a photodetector is attached and a second unit to which a light source for irradiating excitation light to a sample to be measured is attached. Is preferably detachably attached to the second unit. Since only the first unit is removed from the second unit and the applied voltage value of the photodetector of the first unit can be set using another light source, the applied voltage value is set on the second unit side. A light source and means for adjusting the intensity of input light are not required, and the number of parts is reduced, resulting in a reduction in cost.

  In a calibration method for an optical measurement device including a plurality of multiplication type photodetectors that receive light and convert it into an electrical signal, the step of applying an initial voltage to each photodetector differs from the light intensity, and a predetermined The step of inputting at least three types of input light included in the light intensity range to the light detector, the light intensity change rate of the three types of input light, and the three types of outputs output from the light detector according to the input of the input light Determining whether the relative ratio of the value to the output change rate is constant within a predetermined range, and if the relative ratio between the light intensity change rate and the output change rate is not constant within the predetermined range, Adjusting the voltage applied to the photodetector so as to be constant within a predetermined range and setting the applied voltage value.

  According to the calibration method of the optical measuring device according to the present invention, it is possible to set an applied voltage value for each of the multiplication type photodetectors so that output characteristics with respect to input light of each detector in a predetermined light intensity range are constant. As a result, an applied voltage value corresponding to the characteristics of the photodetector is applied to each photodetector, and the measurement accuracy of light included in the predetermined light intensity range can be improved.

  Further, in the calibration method of the optical measuring device, a step of applying an applied voltage value corresponding to each of the plurality of photodetectors to each of the plurality of photodetectors, and a plurality of photodetectors to which the applied voltage values are applied A step of inputting reference input light, and a step of calculating a correction constant for approximating output characteristics of output values output from a plurality of photodetectors by input of the reference input light to predetermined reference output characteristics It is preferable to further include Based on the correction constant, correction can be made so that the output values for the input light of the same intensity become substantially the same value, individual differences among a plurality of photodetectors can be reduced, and measurement accuracy can be improved.

  According to the present invention, individual differences among a plurality of photodetectors can be reduced, and measurement accuracy can be improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram schematically showing a delayed luminescence measuring apparatus. As shown in FIG. 1, a delayed luminescence measuring device (light measuring device) 1 is a device that measures delayed luminescence of a photosynthetic sample such as algae. When excitation light is irradiated to a cell into which a sample in which a photosynthetic sample has been cultured has been dispensed, delayed light emission is generated from the photosynthetic sample by irradiation with the excitation light. The light intensity (amount of luminescence) of delayed luminescence (also called “delayed fluorescence”) decreases with time, and by measuring this change in intensity, the effects of harmful environmental factors on the photosynthetic sample can be evaluated. . First, this evaluation will be described.

(Evaluation of environmental factors)
When a photosynthetic sample such as algae is irradiated with excitation light, the photosynthetic sample performs photosynthetic metabolism and grows cells. In photosynthetic metabolism, light energy absorbed by a photosynthetic pigment is transmitted by a plurality of chemical reactions and converted into energy necessary for cell growth. In the process, reactions that serve as energy sources for delayed luminescence such as enzyme generation, photo-chemical energy conversion, and CO ₂ absorption sequentially occur. As a result, photons are generated at different timings (emission), and the sum of these emissions is measured as a weak delayed emission of the entire photosynthetic sample.

  When harmful environmental factors act on the photosynthetic sample, the intracellular metabolism changes, and the temporal change in the light intensity of delayed luminescence becomes different compared to the case where the environmental factors do not act. Furthermore, the influence on delayed light emission differs for each environmental factor. That is, by comparing the time course of delayed luminescence resulting from photosynthetic samples exposed to environmental factors and the time course of delayed luminescence resulting from photosynthetic samples not exposed to environmental factors, a particular environmental factor can Can be evaluated.

(Delayed luminescence measuring device)
The delayed luminescence measuring apparatus 1 is an apparatus that can simultaneously and independently measure delayed luminescence generated from a plurality of samples composed of photosynthetic samples.

  The delayed light emission measurement device 1 includes a plurality of measurement units 10, an arithmetic unit 20, and a control unit 30. The measurement unit 10 and the arithmetic unit 20 are connected by a first cable 41, and the arithmetic unit 20 and the control unit 30 are connected by a second cable 42. Further, the control unit 30 and the measurement unit 10 are connected by a third cable 43.

  Since the plurality of measurement units 10 have the same configuration, only one measurement unit 10 will be described, and the other measurement units 10 will be denoted by the same reference numerals and the description thereof will be omitted. The measurement unit 10 includes a sample placement unit 11, a delayed light emission detector P, a condensing optical system 12, an excitation light source 13, a transmission light source 14, a transmission light detector 15, a first shutter 16 and a second shutter 17. These components are accommodated in the housing 18.

  The sample placement unit 11 is a part for placing a sample to be measured, and is disposed in the sample chamber R. The sample chamber R is a dark box in which a sample can be taken in and out by opening and closing the door, and light from the outside is blocked when the door is closed. The sample placement unit 11 is configured so that a cell containing a photosynthesis sample as a sample can be placed. The sample placement unit 11 may be configured so that the sample can be introduced from the outside of the housing 18 by a liquid feed pump or the like.

  The delayed luminescence detector (multiplier type photodetector) P receives the delayed luminescence generated by the irradiation of the sample with the excitation light, and converts the received delayed luminescence into an electrical signal corresponding to the light intensity (emission amount). Then, an electrical signal corresponding to the applied voltage is output to the arithmetic unit 20 as an output value. The delayed light emission detector P is configured by using a multiplication type photodetector such as a photomultiplier tube or an avalanche photodiode, for example.

  The condensing optical system 12 is provided so as to collect the weak delayed light emission generated by the irradiation of the excitation light to the sample and guide the condensed delayed light emission to the delayed light emission detector P.

  The excitation light source 13 irradiates the sample installed in the sample installation unit 11 with light (excitation light). The excitation light source 13 should just be able to radiate | emit the light wavelength (280-800 nm) effective for the photosynthesis of a plant, for example, a light emitting diode, a semiconductor laser element, or a light bulb is used. The excitation light source 13 may be a monochromatic light source or a light source combining a plurality of light sources. The light emission method of the excitation light source 13 is not limited, for example, a method of continuously emitting light for a predetermined time, a method of pulse-lighting in an arbitrary pattern, a method of sequentially emitting a plurality of light sources having the same or different wavelength characteristics, and a plurality of methods A method of simultaneously emitting light from the two light sources can be considered.

  The transmitted light source 14 irradiates the sample with transmitted light, and the transmitted light detector 15 measures transmitted light and scattered light transmitted through the sample.

  The first shutter 16 is disposed between the condensing optical system 12 and the sample placement unit 11 in order to optically fractionate the condensing optical system 12, the delayed light emission detector P, and the sample chamber R. It can be opened and closed freely. By closing the first shutter 16, it is possible to prevent light from the excitation light source 13 and the transmission light source 14 from directly entering the condensing optical system 12 and the delayed light emission detector P. As a result, light emission (afterglow) of components such as a condensing optical system can be prevented. The first shutter 16 may be provided at a position closer to the delayed light emission detector P than the condensing optical system 12.

  The second shutter 17 is disposed between the excitation light source 13 and the sample setting unit 11 in order to optically fractionate the excitation light source 13 and the sample chamber R, and is provided to be freely opened and closed. When the second shutter 17 is closed, the second shutter 17 blocks the light irradiated from the excitation light source 13 to the sample setting unit 11, and a slight afterglow generated immediately after the excitation light source 13 is turned off is irradiated to the sample setting unit 11. Is prevented.

  The arithmetic unit 20 specifically corresponds to a PC (Personal Computer) or the like, and is configured by hardware such as a CPU (Central Processing Unit) or a memory, and includes a signal processing unit 21, an input / output unit 22, a calculation unit 23, and a storage. The unit 24 is provided.

  An output value is input from the delayed light emission detector P to the signal processing unit 21. The plurality of delayed light emission detectors P independently measure the light intensity of delayed light emission, and input the measurement results for each elapse of a predetermined time to the signal processing unit 21 as output values. In the signal processing unit 21, the output value input from the delayed light emission detector P is temporarily stored in association with the delayed light emission detector P, and input to the calculation unit 23 in a predetermined order.

  The calculation unit 23 stores the data input from the signal processing unit 21 in the storage unit 24 and performs calculation analysis and evaluation based on the data stored in the storage unit 24. Further, the calculation unit 23 corrects the output value based on the level correction value Lc stored in the storage unit 24 in association with each of the plurality of delayed light emission detectors P, and outputs the corrected output value to the input / output unit 22. Output. Further, the calculation unit 23 inputs an applied voltage value stored in the storage unit 24 in association with each delayed light emission detector P to the control unit 30. The applied voltage value and the level correction value Lc will be described later.

  The input / output unit 22 includes an interface capable of inputting data necessary for analysis, and further outputs the result analyzed and evaluated by the calculation unit 23, for example, displays on a display. In addition, the input operation of the measurer is accepted, and a signal based on the input operation is input to the calculation unit 23.

  In the storage unit 24, output values input from the delayed light emission detectors P every predetermined time are stored in association with each of the plurality of delayed light emission detectors P. Further, the storage unit 24 stores the applied voltage value in association with each of the plurality of delayed light emission detectors P, and further stores the level correction value Lc of the output value in association with each of the delayed light emission detectors P. Has been. The level correction value Lc corresponds to a correction constant. Hereinafter, the applied voltage value and the level correction value Lc will be described.

  Each of the plurality of delayed light emission detectors P has a specific output characteristic with respect to the light input, and the range of the light intensity (light quantity) of the input light in which an ideal output characteristic is obtained in a state where a predetermined voltage is applied. Is different for each delayed light emission detector P. Here, by adjusting the voltage applied to the delayed light emission detector P, it is possible to adjust the range of the light intensity of the input light from which ideal output characteristics can be obtained. For example, the light intensity including weak delayed light emission Can be adjusted to be in range. The applied voltage value according to the present embodiment is such that the light intensity ranges in which ideal output characteristics can be obtained in a plurality of delayed light emission detectors P are close to each other, and delayed light emission is accurately measured in all delayed light emission detectors P. The voltage is adjusted for each of the delayed light emission detectors P so that it is possible.

The ideal output characteristics will be specifically described with reference to FIG. FIG. 16 is a log-log graph showing the relationship of the output value with respect to the light intensity of the input light when the voltage applied to a certain delayed light emission detector P is changed to 700V, 800V and 900V. As shown in FIG. 16, the output value characteristic with respect to the light intensity of the input light is a region in which the output value hardly changes even when the light intensity of the input light changes (for example, the light intensity is 1 or less and 1 × 10 ⁵ The above region) and a region (dynamic range) in which the output value increases as the light intensity increases. Furthermore, also in the dynamic range, the characteristics of the output value with respect to the light intensity of the input light are divided into a region where linearity is obtained and a region where linearity is not obtained. The ideal output characteristic in the present invention refers to a region where the characteristic of the output value with respect to the light intensity of the input light is linear. In the graph of the logarithm of the optical output with respect to the input light under the respective voltage conditions, the range of the optical input having linearity is approximately 1 × 10 ^{2 in the} case of 700 V (here, 10 ² = 40 fW / cm ² ) to approximately 2 × 10 ⁵ , approximately 1 × 10 to approximately 1 × 10 ⁵ for 800V, and approximately 1 × 10 ² to approximately 2 × 10 ⁴ for 900V. In this way, by changing the voltage applied in one photodetector, the range of the optical input having linearity in the logarithm of the optical output with respect to the input light can be adjusted.

  Next, the level correction value Lc will be described. The plurality of delayed light emission detectors P have different output characteristics of output values with respect to input light. Therefore, even if an applied voltage value corresponding to each delayed light emission detector P is applied to each delayed light emission detector P, the output value for input light having the same light intensity is different. The level correction value Lc is a constant for correcting the output characteristics in a state where the applied voltage value is applied to the delayed light emission detector P to be approximated by the plurality of delayed light emission detectors P. In this embodiment, the output characteristics can be substantially matched by multiplying the output value by the level correction value Lc.

  The control unit 30 includes an operation control unit 31 and a voltage adjustment unit 32. The operation control unit 31 is configured by hardware such as a CPU and a memory, for example, and performs operation control of the components of the measurement unit 10 and the voltage adjustment unit 32 in accordance with instructions from the calculation unit 23. For example, the operation control unit 31 can control the light conditions (irradiation timing, light quantity, wavelength, pulse width, irradiation time, etc.) of the excitation light emitted from the excitation light source 13. Furthermore, the operation control unit 31 can control the detection of the light intensity of delayed emission in a predetermined time, and controls the detection time, the detection time, and the like. Furthermore, the operation control unit 31 can control opening and closing of the first shutter 16 and the second shutter 17. Further, the operation control unit 31 can control the voltage applied to the delayed light emission detector P by the voltage adjustment unit 32.

  A plurality of voltage adjustment units 32 are provided corresponding to each of the delayed light emission detectors P, and adjusted so that a predetermined applied voltage value is applied to the delayed light emission detector P in response to an instruction from the operation control unit 31. To do.

  In addition, the structure of the arithmetic unit 20 and the control unit 30 is not limited to this, For example, one computer may have the function of the arithmetic unit 20 and the control unit 30 together.

(Adjustment method of delayed luminescence measuring device)
When evaluating delayed luminescence of photosynthetic samples, use equal parts of photosynthetic samples obtained from the same culture to adjust the standard samples that do not contain environmental factors and the exposed samples that contain environmental factors. Measure delayed luminescence from. In that case, the delayed luminescence measuring device 1 uses a plurality of delayed luminescence detectors P to measure simultaneously in order to make the time from the start of the cultivation of the photosynthetic sample to the exposure and measurement of environmental factors the same. I do.

  When simultaneously measuring using a plurality of delayed light emission detectors P, individual differences in output characteristics of the delayed light emission detectors P become a problem. For example, in the delayed light emission detector P, even if the operating conditions such as the applied voltage are the same, there are individual differences in the output value (gain) with respect to the light input, the detection upper limit and the lower limit, and the characteristics of the output value with respect to the light input are different. When the delayed light emission detector P is used for simultaneous measurement, variation occurs. In particular, delayed light emission is weak light with extremely low light intensity, and furthermore, the light intensity of delayed light emission changes in the range of 4 to 5 digits over time, and changes in several seconds after extinguishing the excitation light irradiation. Has a feature of large. Therefore, when measuring delayed luminescence using a plurality of delayed luminescence detectors P, the influence of individual differences of the delayed luminescence detectors P is very large. Therefore, in the present embodiment, adjustment for reducing the individual difference of the delayed light emission detector P is performed before measuring the delayed light emission. Hereinafter, the adjustment method of the delayed luminescence measuring apparatus 1 will be described with reference to FIGS.

  When adjusting the delayed luminescence measuring apparatus 1, the adjustment process is performed independently for each of the plurality of delayed luminescence detectors P. First, terms used in the description of the adjustment process will be described.

(1) Delayed light emission is extremely weak light that decreases with the passage of time, and the range of the minimum and maximum values of delayed light intensity is a very special value of 4 or 5 digits. Light. As an example, the intensity of delayed light emission at a certain moment is about 40 fW / cm ² (40 × 10 ⁻¹⁵ W / cm ² ) as light energy at a wavelength of 660 nm, which is very weak. In the following description, the light intensity of delayed emission is expressed using an arbitrary unit (U). For example, when the change range of the light intensity of delayed light emission is expressed using an arbitrary unit (U), it becomes 1 (U) to 10 ⁴ (U). Here, if 10 ² (U) = 40 fW / cm ² , the range of change in the light intensity of delayed emission is 1 (U) to 10 ⁴ (U). (2) The predetermined light intensity range in the present embodiment corresponds to delayed light emission, the light intensity is very small, and the ratio of the maximum value to the minimum value is a four-digit range. Specifically, the minimum value was 1 (U) and the maximum value was 10 ⁴ (U).
(3) The three types of reference lights L1, L2, and L3 irradiated to the delayed light emission detector P in the applied voltage value setting process are set to light intensities included in the predetermined light intensity range, and the first reference light L1 The light intensity was set to 1 (U), the light intensity of the second reference light L2 was set to 10 ² (U), and the light intensity of the third reference light L3 was set to 10 ⁴ (U).
(4) The dynamic range is a range between a detection lower limit value and a detection upper limit value. The minimum value and the maximum value of the predetermined light intensity are within the dynamic range of the delayed light emission detector P, and the dynamic range D of the delayed light emission detector P covers the predetermined light intensity range. In addition, the characteristics of the output value with respect to the light intensity of the input light in the dynamic range are divided into a region where linearity is obtained and a region where linearity is not obtained.
(5) The reference output value S described in the level correction value calculation process is an arbitrary numerical value set in advance to approximate the output values from the plurality of delayed light emission detectors P, and outputs a predetermined reference. It corresponds to a characteristic.

The adjustment process is executed by an operation procedure according to the flowchart shown in FIG. In FIG. 2, three delayed emission detectors P ₁ , P ₂ , P ₃ of a first delayed emission detector P ₁ , a second delayed emission detector P ₂ and a third delayed emission detector P ₃ are used. ₃ illustrates an example in which the adjustment process is executed on ₃ . Note that the processing performed for each of the first delayed light emission detector P ₁ , the second delayed light emission detector P _2, and the third delayed light emission detector P ₃ is the same, and therefore the first delayed light emission detection. It focuses on processing for vessels P _1, the description of the processing for the second delayed luminescence detector P ₂ and the third delayed luminescence detector P ₃ is omitted.

  When the adjustment process is started, the operation process is executed in the order of the initial applied voltage setting process (step 1), the applied voltage value setting process (step 2), and the level correction value calculating process (step 3). First, the initial applied voltage setting process will be described.

(Initial applied voltage setting process)
The initial applied voltage setting process is executed by an operation procedure according to the flowchart shown in FIG. When starting the initial application voltage setting process, a minimum operation control unit 31 closes the first shutter 16 of the measuring unit 10, it instructs the voltage adjusting unit 32, capable of obtaining a signal output from the delay emission detector P ₁ the voltage is applied to the delayed luminescence detector P ₁ as the first voltage (step 11). Thereafter, the delayed luminescence detector P _1, the optical input is no state (hereinafter referred to as "dark".) Measures the measurement signal output (hereinafter, referred to as "dark value") is input to the arithmetic unit 20 (Step 12 ). Note that the dark value, by applying a voltage, an error value light input is output despite the delayed luminescence detector P ₁ no.

Next, the control unit 30 controls the light intensity of the excitation light source 13 and irradiates the initial reference light from the excitation light source 13 (step 13). The initial reference light is preferably between the minimum value and the maximum value of delayed light intensity. Furthermore, since it is desirable that it is between the minimum value and the maximum value when expressed in a logarithmic scale, the light intensity of the initial reference light is set to 10 ² (U).

Next, the delayed light emission detector P ₁ detects the initial reference light, measures the signal output (elementary output), and inputs the measured signal output to the arithmetic unit 20 as an element output value (step 14). Thereafter, the control unit 30 turns off the initial reference light (step 15), and the calculation unit 23 of the calculation unit 20 calculates the dark subtraction output value C by subtracting the dark value from the raw output value (step 16). Thereafter, the arithmetic unit 23, the dark subtraction output value C is determined whether satisfies a predetermined output reference (step 17), if satisfied, the initial application of a voltage applied to the delayed luminescence detector P ₁ The voltage is set and stored in the storage unit 24 (step 18). In the present embodiment, the predetermined output standard is set in the range of 900 (U) to 1100 (U), that is, 1000 (U) ± 10 (%).

On the other hand, when the calculation unit 23 determines that the dark subtraction output value C does not satisfy the predetermined output standard (step 17), the operation unit 23 stores data indicating that the output standard is not satisfied in the operation control unit 31 of the control unit 30. input. Then, the operation control unit 31 changes the voltage applied to the delayed luminescence detector P ₁ instructs the voltage adjusting unit 32 changes the initial applied voltage (step 19), the delayed luminescence detector P _1, again Dark measurement is performed (step 12). Thereafter, subsequent processing is sequentially executed to set an initial applied voltage and stored in the storage unit 24 (step 18). In the present embodiment, 600 as the initial voltage applied delayed luminescence detector P ₁ (V) is set.

As described above, in the delayed luminescence measuring device 1, until the dark subtraction output value C satisfies a predetermined output reference, is changed the voltage applied to the delayed luminescence detector P _1, the calculation of the dark subtraction output value C, Evaluation is performed. When the initial applied voltage is set, is stored in the storage unit 24 as the initial application voltage corresponding to the delayed luminescence detector P _1, the initial applied voltage setting process is completed. Note that the dark measurement and the elementary output measurement in the initial applied voltage setting process may be reversed in order.

  As shown in FIG. 2, when the initial applied voltage setting process (step 1) is completed, the applied voltage value setting process (step 2) is executed. The applied voltage value setting process is executed by an operation procedure according to the flowchart shown in FIG.

When the applied voltage value setting process starts, the calculation unit 23 of the calculation unit 20 reads the initial application voltage (initial voltage) corresponding to the delayed light emission detector P ₁ stored in the storage unit 24 and controls the initial application voltage. Input to the operation control unit 31 of the unit 30. Operation control unit 31 instructs the voltage adjusting unit 32 applies a 600 (V) is the initial voltage applied to the delayed luminescence detector _{P 1} (step 21).

Then delayed luminescence detector P ₁ measures the dark, is input to the arithmetic unit 20 a measurement signal output as the first dark value (step 22). The calculation unit 23 stores the received first dark value in the storage unit 24. Next, the control unit 30 controls the excitation light source 13 to irradiate the delayed emission detector P1 with the _first reference light L1 having the lowest intensity among the three types of reference lights L1, L2, and L3 having different intensities. (Step 23).

Next, the delayed luminescence detector P ₁ detects the first reference light L1 measured signal output (element output), and inputs to the arithmetic unit 20 a measurement signal outputted as a first element output value (step 24). When receiving the first prime output value, the calculation unit 23 stores the first prime output value in the storage unit 24. Thereafter, the control unit 30 turns off the first reference light L1 (step 25). The dark measurement and the elementary output measurement may be reversed.

Next, the calculation unit 23 reads the first dark value and the first prime output value stored in the storage unit 24, subtracts the first dark value from the first prime output value, and the first dark subtraction output value C1. Is calculated (step 26). The calculation unit 23 stores the first dark subtraction output value C1 in the storage unit 24. Delayed luminescence detector first dark subtraction output value C1 of P ₁ (see FIGS. 7 and 8) is a "5". FIG. 8 shows a log-log graph in which the horizontal axis represents input light intensity and the vertical axis represents dark subtraction output.

Next, the delayed luminescence detector P ₁ is again measured dark, and inputs to the arithmetic unit 20 a measurement signal output as the second dark value (step 27). The calculation unit 23 stores the received second dark value in the storage unit 24. Next, the control unit 30 controls the excitation light source 13 to irradiate the second reference light L2 (step 28).

Delayed luminescence detector P _1, the signal output in the state where the second reference light L2 is input (the element output) is measured and input to the arithmetic unit 20 a measurement signal output as the second element output value ( Step 29). When receiving the second prime output value, the computing unit 23 causes the storage unit 24 to store the second prime output value. Thereafter, the control unit 30 turns off the second reference light L2 (step 30). The dark measurement and the elementary output measurement may be reversed.

Next, the computing unit 23 reads the second dark value and the second elementary output value stored in the storage unit 24, subtracts the second dark value from the second elementary output value, and obtains a second dark subtracted output value C2. Is calculated (step 31). The computing unit 23 stores the second dark subtraction output value C2 in the storage unit 24. Note that the second dark subtraction output value of the delayed luminescence detector _{P 1} C2 (FIGS. 7 and 8) is "1005".

Next, the delayed luminescence detector P ₁ is again measured dark, and inputs to the arithmetic unit 20 a measurement signal output as a third dark value (step 32). The calculation unit 23 stores the received third dark value in the storage unit 24. Next, the control unit 30 controls the excitation light source 13 to irradiate the third reference light L3 (step 33).

Next, the delayed luminescence detector P _1, the signal output in the state where the third reference light L3 is input (the element output) is measured, the arithmetic unit 20 a measurement signal output as a third element output value Input (step 34). When receiving the third prime output value, the arithmetic unit 23 stores the third prime output value in the storage unit 24. Thereafter, the control unit 30 turns off the third reference light L3 (step 35). Note that the measurement of the third dark value and the measurement of the third elementary output value may be reversed.

Next, the computing unit 23 reads the third dark value and the third elementary output value stored in the storage unit 24, subtracts the third dark value from the third elementary output value, and obtains a third dark subtracted output value C3. Is calculated (step 36). The calculation unit 23 stores the third dark subtraction output value C3 in the storage unit 24. The third dark subtraction output value C3 of the delayed luminescence detector _{P 1} (FIGS. 7 and 8) is "90000".

  In the processing from step 21 to step 36 described above, the initial applied voltage is applied, and three types of reference lights L1, L2, and L3 having different intensities are input to the delayed light emission detector T. Further, first to third dark subtraction output values C1, C2, and C3 are derived from the first to third elementary output values based on the reference lights L1, L2, and L3 and the first to third dark values. .

  Next, the computing unit 23 changes the light intensity change rate (light intensity change rate) of the input light derived from the three types of reference lights L1, L2, and L3, the first dark subtraction output value C1, and the second dark subtraction output value C2. And whether the relative ratio to the output change rate derived from the third dark subtraction output value C3 is constant within a predetermined range, that is, whether or not the logarithmic graph has linearity (linearity) ( Step 37).

A method for determining linearity in a log-log graph is shown below. The light intensity of the a-th reference light is set to La, the subtraction output value derived based on the a-th reference light is set to Ca, and the light intensity of the b-th (b ≠ a) reference light is set to The subtracted output values derived based on Lb and the b-th reference light are respectively set as Cb. At this time, when the relationship of the output value C to the light intensity L of the reference light is plotted on a log-log graph, the slope Nab of the straight line connecting the two points (La, Ca) and (Lb, Cb) is Indicated by
Nab = {Log (Ca / Cb) / Log (La / Lb)}
Here, Log (La / Lb) is the light intensity change rate, and Log (Ca / Cb) is the output change rate. Whether or not the graph is linear can be determined by checking whether or not Nab for at least three types of reference light is constant within a predetermined range. In other words, the linearity in the log-log graph has a relative ratio between the light intensity change rate of at least three types of input light and the output change rate of the three types of output values output from the photodetector according to the input light input. Judgment can be made based on whether or not it is constant within a predetermined range.
Hereinafter, the case of Nab = 1 will be described in more detail. At this time, the above equation becomes
Log (Ca / Cb) / Log (La / Lb) ≒ 1
Therefore
Log (Ca / Cb) ≒ Log (La / Lb)
Furthermore (Ca / Cb) ≒ (La / Lb)
It becomes. Therefore, hereinafter, the light intensity change rate is (La / Lb) and the output change rate is (Ca / Cb).

When the relative ratio between the light amount change rate of the input light and the output change rate of the output value is constant, the delayed light emission detector P ₁ accurately adjusts the light intensity within the predetermined range. It can be detected. The three types of reference lights L1, L2, and L3 are lights included in a predetermined light intensity range corresponding to delayed emission, and the light intensity change rate of the input light derived from the reference lights L1, L2, and L3, Whether the relative ratio between the first dark subtraction output value C1, the second dark subtraction output value C2, and the output change rate derived from the third dark subtraction output value C3 is constant, that is, whether or not it has linearity. It is possible to evaluate whether or not the delayed light emission can be accurately measured. Incidentally, the dynamic range D of the delayed luminescence detector P _1, the reference light L1, L2, L3 is substantially cover a predetermined light intensity ranges subsumed. Hereinafter, the determination of whether or not to have linearity performed by the calculation unit 23 will be specifically described.

In the storage unit 24, the light intensity (first intensity) of the first reference light L1, the light intensity (second intensity) of the second reference light L2, and the light intensity (third) of the third reference light L3. Intensity) is stored. Further, the storage unit 24 includes a first light intensity change rate obtained by dividing the intensity 10 ² (U) of the second reference light L2 by the intensity 1 (U) of the first reference light L1, and a third reference light. and from L3 strength ¹⁰ 4 (U) a second light intensity change ratio obtained by dividing the intensity ¹⁰ 2 of the second reference light L2 (U) is stored. In the present embodiment, the first light intensity change rate and the second light intensity change rate are both “100”.

  The calculation unit 23 reads the first light intensity change rate and the second light intensity change rate stored in the storage unit 24, and the first dark subtraction output value C1 (first output value) and the second dark subtraction output. The value C2 (second output value) and the third dark subtraction output value C3 (third output value) are read. Further, the calculation unit 23 calculates the first output change rate C2 / C1 by dividing the first dark subtraction output value C1 from the second dark subtraction output value C2, and the second dark subtraction output value C3. The second output change rate C3 / C2 is calculated by dividing the output value C2.

  Next, the calculation unit 23 determines whether or not the first output change rate C2 / C1 is approximate to the first light intensity change rate “100”, for example, is included in a range of ± 10 (%). Determine. When the first output change rate C2 / C1 approximates the first light intensity change rate “100”, the relative ratio between the first output change rate C2 / C1 and the first light intensity change rate “100” is approximately 1. Pair one. Further, the calculation unit 23 determines whether or not the second output change rate C3 / C2 is approximate to the second light intensity change rate “100”, for example, whether it is included in an error range of ± 10 (%). Determine. The relative ratio between the second output change rate C3 / C2 and the second light intensity change rate “100” and the relative ratio between the second output change rate C3 / C2 and the second light intensity change rate “100” are both approximately. One to one. The relative ratio between the first output change rate C2 / C1 and the first light intensity change rate “100” and the relative ratio between the second output change rate C3 / C2 and the second light intensity change rate “100” are both approximately 1. In the case of a one-to-one relationship, the relative ratio between the light intensity change rate of the input light and the output change rate based on the dark subtraction output value is constant within a predetermined range, and the logarithmic graph has linearity.

A specific discussion will be given with reference to FIGS. If the voltage applied to the delayed luminescence detector P ₁ is 600 (V) of the initial applied voltage, the first output change rate C2 / C1 is "201", the first light intensity change rate "100" On the other hand, it exceeds the predetermined error range. The second output change rate C3 / C2 is “90”, which is within a predetermined error range with respect to the second light intensity change rate “100”. In this case, the relative ratio between the first output change rate C2 / C1 and the first light intensity change rate and the relative ratio between the second output change rate C3 / C2 and the second light intensity change rate are constant. In other words, the logarithmic graph (see FIG. 8) does not have linearity.

In the case of delayed luminescence detector _P voltage applied to the ₁ 660 (V), the first output change rate C2 / C1 is "91", for the first light intensity change rate "100" Are included in a predetermined error range. The second output change rate C3 / C2 is “103”, which is within a predetermined error range with respect to the second light intensity change rate “100”. In this case, the relative ratio between the first output change rate C2 / C1 and the first light intensity change rate and the relative ratio between the second output change rate C3 / C2 and the second light intensity change rate are constant. The logarithmic graph (see FIG. 8) has linearity.

Further, when the voltage applied to the delayed luminescence detector _{P 1} is 726 (V), the first output change rate C2 / C1 is "65", for the first light intensity change rate "100" The specified error range is exceeded. The second output change rate C3 / C2 is “87”, which exceeds the predetermined error range with respect to the second light intensity change rate “100”. In this case, the relative ratio between the first output change rate C2 / C1 and the first light intensity change rate and the relative ratio between the second output change rate C3 / C2 and the second light intensity change rate are constant. In other words, the logarithmic graph (see FIG. 8) does not have linearity. Therefore, it can be confirmed that a suitable applied voltage value is 660 (V).

As shown in FIG. 4, when it is determined in step 37 that the calculation unit 23 has linearity, the calculation unit 23 stores the voltage applied to the delayed light emission detector P ₁ in the storage unit 24 as an applied voltage value ( Step 38). On the other hand, even if it does not have linearity within a predetermined range corresponding to the light intensity of delayed light emission, it can be finely adjusted to have linearity by adjusting the applied voltage. Therefore, when the arithmetic unit 23 determines that it does not have linearity, it performs the following processing for fine adjustment.

Calculation unit 23 first determines whether or not capable of changing the applied voltage, i.e., whether the voltage of the upper limit that can be applied to the delayed luminescence detector P ₁ has already been applied (step 39). For example, is determined in advance a maximum value due maximum straight-line voltages applied delayed luminescence detector P _1, when the voltage has already reached the maximum value, to be determined not to change the applied voltage. Calculation unit 23, when determining not to change the applied voltage, the end of work, to display an error message indicating such replacement of delayed luminescence detector P ₁ to the input-output unit 22 (step 41).

In addition, when it is determined that the applied voltage can be changed (step 39), the calculation unit 23 inputs a new voltage to the control unit 30 so that the applied voltage increases stepwise by, for example, about 10%. in 30 to change the applied voltage so as to apply a new voltage accepted delayed luminescence detector P ₁ (step 40). Thereafter, the processes of Step 22 to Step 37, Step 39, and Step 40 are sequentially repeated until it has linearity within a predetermined range corresponding to the light intensity of delayed light emission or until it is determined that the applied voltage cannot be changed. The applied voltage is adjusted. Then, when it becomes to have a linearity, the operating section 23, the voltage applied to the delayed luminescence detector P ₁ is in the storage unit 24 as the applied voltage value. When the applied voltage value is stored in the storage unit 24, the applied voltage setting process ends.

At an applied voltage value setting process, can set the applied voltage such that the measurement is possible at a predetermined light intensity ranges corresponding to the delayed luminescence in delayed luminescence detector P _1, the delayed luminescence detector P in the measurement process described later _The applied voltage value corresponding to the characteristic of ₁ is applied to each delayed light emission detector P1, so that the measurement accuracy can be improved.

Note that, for example, three patterns of voltage to be applied are set, the voltages of all patterns are applied to evaluate the respective linearities, and the voltage having the optimum linearity is set as the applied voltage value. Good.
In the above embodiment, only the case of Nab = 1 has been described, but the adjustment applied voltage setting process of the present invention is not limited to this. Nab may take any value as long as it is a real number greater than or equal to zero.

  Moreover, in the said embodiment, although the light intensity of input light uses the value common among several detectors, it is not limited to this. As long as the light intensity of the input light is within a predetermined light intensity range, each detector can take an arbitrary value.

  Further, when the cause is that the dark subtraction output value C1 is too large, the applied voltage is lowered, and when the cause is that the dark subtraction output value C1 is too small, adjustment is performed such that the applied voltage is increased or the dark subtraction output value is increased. When the cause is that C3 is too small, the applied voltage may be lowered, and when the cause is too large, adjustment may be performed such that the applied voltage is raised.

As shown in FIG. 2, when the applied voltage value setting process (step 2) ends, a level correction value calculation process (step 3) is executed. Even applying the application voltage value corresponding to the delay emission detector P _1, the output value for the input light having the same intensity are different. Therefore, the output characteristic in the state of applying the application voltage value to the delayed luminescence detector P ₁ is performing level correction value calculation processing in order to approximate the output characteristic of the predetermined criteria. The level correction value calculation process is executed by an operation procedure according to the flowchart shown in FIG.

When the level correction value calculation process starts, the calculation unit 23 reads the applied voltage value corresponding to the delayed light emission detector P ₁ stored in the storage unit 24, and sends the applied voltage value to the operation control unit 31 of the control unit 30. input. Operation control unit 31 instructs the voltage regulator 32, applies an applied voltage value to the delayed luminescence detector P ₁ (step 51). In the following description, the case where the applied voltage value is set to 660 (V) will be described as an example.

Next, the delayed luminescence detector P ₁ measures the dark, is input to the arithmetic unit 20 a measurement signal output as the correction dark value (step 52). Next, the operation control unit 31 controls the excitation light source 13 so that the light intensity becomes a preset correction reference light (reference input light), and irradiates the delayed light emission detector P ₁ with the correction reference light. (Step 53). In the present embodiment, the light quantity of the reference light for correction is set to 10 ² (U).

Next, the delayed luminescence detector P _1, the signal output of the correction reference light (containing output) is measured and input to the arithmetic unit 20 the output signals measured as a correction element output value (step 54). Upon receiving the correction element output value, the calculation unit 23 of the calculation unit 20 stores the correction element output value in the storage unit 24. Next, the control unit 30 controls the excitation light source 13 to turn off the correction reference light (step 55). It should be noted that the dark measurement order and the elementary output measurement order may be reversed.

  Next, the calculation unit 23 reads the correction element output value and the correction dark value stored in the storage unit 24, and calculates the reference dark subtraction output C4 by subtracting the correction dark value from the correction element output value. (Step 56). Thereafter, the calculation unit 23 calculates a level correction value Lc such that the reference dark subtraction output C4 matches the predetermined reference output value S within a predetermined error range (step 57). The level correction value Lc is obtained by the following formula 1.

  Lc = S / C4 (Equation 1)

Next, the computing unit 23 stores the calculated level correction value Lc in the storage unit 24 (step 58). When the calculated level correction value Lc is stored in the storage unit 24, the level correction value calculation processing is ended, the first adjustment processing on the delayed luminescence detector P ₁ is completed.

Incidentally, the level correction value calculation processing (step 3) is performed similarly in the second delay emission detector P ₂ and the third delayed luminescence detector P _3. That is, in the second delayed light emission detector P ₂ and the third delayed light emission detector P ₃ , the applied voltage value is applied, and the corrected reference light (reference input light) is input to calculate the level correction value Lc. Is done. By deriving the level correction value Lc, the output characteristics of the delayed light emission detectors P ₁ , P ₂ , P ₃ in the state where the applied voltage value is applied substantially coincide with the predetermined reference output characteristics. Thus, the output values for the input light of the same intensity can be corrected so as to be substantially the same value, individual differences among the plurality of delayed light emission detectors P ₁ , P ₂ , P ₃ are reduced, and the measurement accuracy is improved. be able to.

Adjustment processing performed on the first delayed luminescence detector P ₁ is performed similarly for the second delayed luminescence detector P ₂ and the third delayed luminescence detector P _3, respectively the applied voltage Value setting and level correction value Lc are set. For example, as shown in FIG. 9, the applied voltage value of the _first delayed emission detector P ₁ is set to 660 (V), and the applied voltage value of the second delayed emission detector P ₂ is 600 (V). The applied voltage value of the _third delayed light emission detector P ₃ is set to 726 (V).

When an applied voltage value as shown in FIG. 9 is applied to each of the first delayed emission detector P ₁ , the second delayed emission detector P ₂ and the third delayed emission detector P ₃ , The graph is as shown in FIG. FIG. 10 is a log-log graph in which the horizontal axis represents the amount of input light and the vertical axis represents the dark subtraction output value. As shown in FIG. 10, in each of the first delayed emission detector P ₁ , the second delayed emission detector P _2, and the third delayed emission detector P ₃ , a predetermined value corresponding to the light intensity of the delayed emission is obtained. It has linearity in the range of.

However, the dark subtraction output values for the same amount of input light are slightly different. Therefore, when correction is performed by multiplying each dark subtraction output value by the level correction value Lc as shown in FIG. 11, the output values after the correction are substantially the same and the output characteristics are as shown in FIGS. Approximate. Note that. The level correction value Lc of the first delayed light emission detector P ₁ is set to “6.45”, the level correction value Lc of the second delayed light emission detector P ₂ is set to “12.35”, and the third The level correction value Lc of the delayed light emission detector P ₃ is set to “5.56”. FIG. 13 is a log-log graph similar to FIG.

  The level correction value described above may be calculated using, for example, the dark subtraction output value C2 obtained in the applied voltage adjustment process, and in this case, input of new correction reference light is unnecessary. It becomes.

  Also, a plurality of level correction values can be calculated by inputting a plurality of correction reference lights having different intensities, and the level correction value to be applied can be changed depending on the magnitude of the dark subtraction output C4.

  In addition, a function indicating the relationship between the elementary output value or the dark subtracted output value and the intensity of the input light is set, and a corrected output value is obtained by substituting the elementary output value or the dark subtracted output value into the function. It may be.

  In addition, since there is a stochastic noise in the delayed light emission detector P, when the light intensity of delayed light emission is low, the stochastic noise value becomes larger than the original output value after correction. There is a case. In this case, if a corrected output value is derived by multiplying the level correction value, for example, by multiplying the level correction value, the level correction value is further multiplied by the stochastic noise larger than the original output value, resulting in an error. Becomes larger. For example, when the level correction value is 1 or more, the influence of the stochastic noise is large, and when the level correction value is 1 or less, the influence of the stochastic noise is small. Such a problem increases the error between the delayed light emission detectors P when comparing the measurement results in the portion where the intensity of the input light due to the measured delayed light emission is low with a plurality of delayed light emission detectors P. . In order to solve this, a predetermined value (offset correction value) may be subtracted from the corrected output value. The correction using the offset correction value may be applied to all dark subtraction output values, or may be applied only when the dark subtraction output is equal to or less than a certain threshold value.

(Measurement process)
Next, a process for measuring delayed light emission using the delayed light emission measuring device 1 adjusted by the above adjustment method will be described. In the present embodiment, the first delayed emission detector P ₁ , the second delayed emission detector P _2, and the third delayed emission detector P ₃ each independently measure the delayed emission of the sample. Note that the measurement processing performed in the first delayed emission detector P ₁ , the second delayed emission detector P _2, and the third delayed emission detector P ₃ is the same, and therefore the first delayed emission detector P 1 ₁ will be mainly described, and the description thereof will be omitted for measurement processing performed in the second delayed luminescence detector P ₂ and the third delayed luminescence detector P _3.

  The measurement process is executed along the flowchart shown in FIG. When the measurement process starts, the calculation unit 23 of the calculation unit 20 inputs an applied voltage value corresponding to the first delayed luminescence measurement device 1 to the control unit 30. When the operation control unit 31 of the control unit 30 receives the applied voltage value, the operation control unit 31 instructs the voltage adjustment unit corresponding to the first delayed luminescence measuring device 1 to apply the applied voltage value to the first delayed luminescence measuring device 1. (Step 61).

Next, the delayed luminescence detector P _1, the signal output of the delayed luminescence from the sample (containing output) is measured and input to the arithmetic unit 20 and the signal output as containing the output value (step 62). Thereafter, the control unit 30 performs the first shutter 16 closes control performs measurement of delayed luminescence detector dark at P _1, is input to the control unit 30 a measurement signal output as dark value (step 63). Next, the arithmetic unit 23 subtracts the dark values from element output value inputted from the delay emission detector P ₁ calculates a dark subtraction output value. Further, the arithmetic unit 23 reads out the level correction value Lc which has been stored in association with the delayed luminescence detector P ₁ in the storage unit 24, the calculated dark subtraction output value, a correction operation to apply, for example, the level correction value Lc Perform (step 64). Thereafter, the calculation unit 23 stores the corrected output value (corrected output value) in the storage unit 24, outputs the corrected output value to the input / output unit 22, and ends the measurement process. In delayed luminescence detector P _1, for example, performs a measurement process of the delayed luminescence for each 0.1 seconds, thereby temporally storing correction output value.

The delayed light emission can be measured with the excitation light source 13 turned off after the excitation light source 13 irradiates the sample with excitation light. While the excitation light source 13 irradiates the excitation light, the first shutter 16 is closed and the second shutter 17 is opened. After a predetermined excitation time has elapsed, the second shutter 17 is closed and the excitation light source 13 is turned off in conjunction. Then, the first shutter 16 is opened, the delayed luminescence emitted from the sample is measured by the delayed luminescence detector P _1. Here, since opening and closing of the first shutter 16 and the second shutter 17 requires a certain time, the opening operation of the first shutter 16, the closing operation of the second shutter, and the excitation light source are turned off simultaneously. Doing afterglow of exciting light or the excitation light will be incident on the delayed luminescence detector P _1. Therefore, it is effective not to simultaneously perform the opening operation of the first shutter 16, the closing operation of the second shutter, and turning off the excitation light source, but shifting each time. For example, after a predetermined time has elapsed, the second shutter 17 is closed, and the excitation light source 13 is turned off in conjunction. Thereafter, the first shutter 16 is opened after a predetermined waiting time until the second shutter 17 is completely closed. It should be noted that the same effect can be obtained by advancing the timing of turning off the excitation light source.

In the case of measuring the weak light delayed luminescence detector P _1, if the element output value measured becomes negative smaller than the dark value, set the minimum value to "1", it becomes negative All the values may be replaced with “1” and output. In this case, the lowest value may be other than “1” by multiplying the dark subtraction output by the level correction value Lc. In order to avoid such inconveniences in the correction processing, the level correction value is multiplied by each of the elementary output value and the dark value, and then the value obtained by multiplying the elementary output value by the level correction value is changed to the level correction value. The value multiplied by may be subtracted.

The calculation unit 23 corrects the output value after correction of the delayed light emission (corrected) measured by each of the first delayed light emission detector P ₁ , the second delayed light emission detector P _2, and the third delayed light emission detector P _3. Output value) is stored in the storage unit 24, the influence of environmental factors on the photosynthetic sample is analyzed and evaluated based on the change with time of the corrected output value, and the evaluation result is output to the input / output unit 22.

  According to the delayed luminescence measuring apparatus 1 described above, an applied voltage value corresponding to the characteristics of the delayed luminescence detector P can be applied to each delayed luminescence detector P, and delayed luminescence composed of weak light can be accurately measured. In addition, since the output value can be corrected so that the output value with respect to the input light when the applied voltage value is applied to the delayed light emission detector P is approximated by the plurality of delayed light emission detectors P, the output with respect to the input light with the same intensity The values can be corrected so as to be substantially the same value, individual differences among the plurality of delayed light emission detectors P can be reduced, and measurement accuracy can be improved.

  As a result, according to the delayed luminescence measuring apparatus 1, a plurality of samples (photosynthesis samples) can be simultaneously measured with high accuracy, and the results can be compared. Thereby, when evaluating the influence of the environmental factor on the photosynthetic sample, it is possible to accurately compare the standard sample prepared by the same preparation procedure without the influence of the environmental factor and the exposed sample having the influence of the environmental factor.

  In particular, as the number of environmental factors to be compared increases, the effect of the delayed luminescence measuring apparatus 1 that can measure a plurality of samples (photosynthesis samples) simultaneously and accurately increases. For example, when a plurality of samples are measured with one delayed luminescence detector, the other samples are in a standby state while the delayed luminescence of one sample is measured. When there are n samples, n × T (s) time elapses from when the first sample is measured to when the last sample is measured. During this period, it is difficult to maintain the same physiological state such as the growth of the photosynthetic sample and environmental response. However, according to the delayed luminescence measuring apparatus 1, the delayed luminescence of a plurality of samples can be simultaneously measured and compared by the plurality of delayed luminescence detectors P, so that the difference in conditions between the samples hardly occurs and the measurement time is T ( s) is sufficient, improving the accuracy of the evaluation, freeing you from the hassle of measuring multiple samples in order, simplifying the measurement, and leading to a reduction in measurement time. improves.

  Further, in the delayed luminescence measuring device 1, the level correction value Lc is stored in the storage unit 24 in association with each of the plurality of delayed luminescence detectors P, so the calculation unit 23 corrects based on the level correction value Lc. The output value can be calculated, and the processing burden associated with the arithmetic processing is small.

  Furthermore, the three types of reference lights L1, L2, and L3 irradiated to the delayed emission detector P when setting the applied voltage value are included in a predetermined light intensity range, and the dynamic range D of the delayed emission detector P is set. Is within the range. Therefore, the delayed light emission detector P can accurately detect the light intensity within the change range of the light emission amount of the delayed light emission.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 14 is a diagram schematically illustrating a delayed luminescence measuring apparatus according to the second embodiment, and FIG. 15 is a diagram schematically illustrating an applied voltage adjusting apparatus. In the delayed luminescence measuring apparatus 2 according to the second embodiment, the same elements and members as those of the delayed luminescence measuring apparatus 1 according to the first embodiment are denoted by the same reference numerals as those of the delayed luminescence measuring apparatus 1. Is omitted.

(Delayed luminescence measuring device)
As shown in FIG. 14, the delayed luminescence measurement device 2 includes the same arithmetic unit 20 and control unit 30 as the delayed luminescence measurement device 1 according to the first embodiment. The delayed light emission measuring device 2 includes a plurality of measurement units 50. Each of the plurality of measurement units 50 has the same configuration, and FIG. 14 shows only one measurement unit 50.

  The measurement unit 50 includes a first unit 51 and a second unit 52. The second unit 52 includes a sample setting unit 53, an excitation light source 54, a second shutter 55, a transmission light source 56, and a transmission light detector 57, and these components are provided in the first housing 58. . The first unit 51 includes a first shutter 61, a condensing optical system 62, and a delayed light emission detector R, and these components are provided in a second housing 65. The first unit 51 is connected to the signal processing unit 21 of the arithmetic unit 20 and the voltage adjustment unit 32 of the control unit 30 through the first connector 63 so as to be connected and separated. Further, the first unit 51 is connected to the first unit via the second connector 64 so as to be connected and separated. As a result, the first unit 51 is configured to be detachable from the second unit 52, the arithmetic unit 20, and the control unit 30.

(Applied voltage adjustment device)
The applied voltage adjustment device 3 is a device for executing the adjustment process described above for the delayed light emission measurement device 2. The first unit 51 of the delayed luminescence measuring device 2 is detached from the second unit 52 and attached to the applied voltage adjusting device 3. The applied voltage adjustment device 3 includes a reference light irradiation unit 70, a voltage adjustment unit 80, and a control unit 90. The first unit 51 is connected to the voltage adjustment unit 80 via the first connector 63 and is connected to the reference light irradiation unit 70 and the control unit 90 via the second connector 64.

  The reference light irradiation unit 70 includes a reference light source 71 that emits light for setting an applied voltage value, and a light amount adjustment unit 72, and the reference light source 71 and the light amount adjustment unit 72 include a third casing 73. Installed inside. In order to set the applied voltage value, it is necessary to change the intensity of the input light stepwise. Therefore, the light amount adjustment unit 72 generates weak light corresponding to delayed light emission, and adjusts the intensity of irradiation light so that at least three steps of intensity changes are possible in order to set the applied voltage value. The light amount adjustment unit 72 uses an ND filter or a wavelength selection filter whose transmittance changes step by step, means for adjusting the light amount of the reference light source 71, a monitor and a shutter for displaying the light amount of the adjusted reference light source 71, and the like. It is configured.

  Specifically, the voltage adjustment unit 80 corresponds to a PC (Personal Computer) or the like, is configured by hardware such as a CPU (Central Processing Unit) or a memory, and includes an input / output unit 81, a calculation unit 82, and a storage unit 83. . The input / output unit 81, the calculation unit 82, and the storage unit 83 have the same configuration as the input / output unit 22, the calculation unit 23, and the storage unit 24 of the delayed light emission measurement device 1 according to the first embodiment, respectively, and are mainly used for adjustment processing. Performs the associated operation process.

  The control unit 90 includes an operation control unit 91 and a voltage adjustment unit 92. The operation control unit 92 controls the operation of the components of the voltage adjustment unit 92 and the reference light irradiation unit 70 in accordance with instructions from the calculation unit 82 of the voltage adjustment unit 80. The voltage adjustment unit R adjusts the applied voltage of the delayed light emission detector R attached to the reference light irradiation unit 70 in accordance with an instruction from the operation control unit R.

  When adjusting the delayed light emission measuring device 2 using the applied voltage adjusting device 3, first, the first unit 51 of the delayed light emission detector R to be adjusted is removed from the second unit 52, and the first unit 51 is adjusted to apply voltage adjustment. Set in the reference light irradiation unit 70 of the apparatus 3. Thereafter, the applied voltage adjustment device 3 sequentially executes the initial applied voltage setting process, the applied voltage value setting process, and the level correction value calculation process in the above-described adjustment process (see FIG. 2) to obtain the applied voltage value and the level correction value Lc. Store in the storage unit 83. The applied voltage value and the level correction value Lc stored in the storage unit 83 are recorded on, for example, a small recording medium and read into the arithmetic unit 20 of the delayed luminescence measuring apparatus 2 via the small recording medium.

  In the delayed luminescence measuring apparatus 2 according to the second embodiment, the first unit 51 provided with the delayed luminescence detector R is detachably attached to the second unit 52. As a result, only the first unit 51 can be removed from the second unit 52 and the applied voltage value can be set using the reference light source 71 provided in the applied voltage adjusting device 3. Therefore, it is not necessary to provide components such as light source selection and arrangement necessary for setting the applied voltage value and light intensity control means in the measurement unit 50 of the delayed light emission measurement device 2, simplifying the device configuration and manufacturing. Simplification and miniaturization, etc., leading to a reduction in manufacturing costs.

  In the second embodiment, the initial applied voltage setting process, the applied voltage value setting process, and the level correction value calculating process in the adjustment process are all performed by the applied voltage adjusting apparatus 3, but the applied voltage adjusting apparatus 3 uses the initial applied voltage. The setting process and the applied voltage value setting process may be performed until the applied voltage value is set, and the level correction value calculation process may be performed by the delayed light emission measuring device 2.

  In the second embodiment, the applied light voltage value and the level correction value Lc set by the applied voltage adjusting device 3 are read by the delayed light emission measuring device 2 via the recording medium. 2 and the applied voltage adjustment device 3 may be connected by a cable or the like so that the applied voltage value and the level correction value Lc can be transmitted directly from the applied voltage adjustment device 3 to the delayed luminescence measuring device 2.

  The present invention is not limited to the above embodiment. For example, the reference light used for setting the applied voltage value is not limited to three types of light having different intensities, and may be four or more types.

It is a figure which shows typically the delayed light emission measuring apparatus which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation | movement procedure of an adjustment process. It is a flowchart which shows the operation | movement procedure of an initial applied voltage setting process. It is a flowchart which shows the operation | movement procedure of an applied voltage value setting process. It is a flowchart which shows the operation | movement procedure of a level correction value calculation process. It is a flowchart which shows the operation | movement procedure of a measurement process. It is a figure which shows the presence or absence of the linearity between the dark subtraction output value for every applied voltage with respect to reference | standard light, and the intensity | strength of input light, and a dark subtraction output value. It is a log-log graph which shows the relationship between the intensity | strength of input light, and a dark subtraction output value. It is a figure which shows the presence or absence of the linearity between the intensity | strength of an input light, and the dark subtraction output value for every applied voltage with respect to the reference light in the state which applied the applied voltage value. It is a log-log graph which shows the relationship between the intensity | strength of input light and the dark subtraction output value in the state which applied the applied voltage value. It is a figure which shows the level correction value with respect to a some delayed light emission detector. It is a figure which shows the output value after correction | amendment with a level correction value. It is a log-log graph which shows the relationship between the intensity | strength of input light, and the output value after correction | amendment. It is a figure showing typically the delayed luminescence measuring device concerning a 2nd embodiment of the present invention. It is a figure which shows an applied voltage adjustment apparatus typically. It is a log-log graph when the light intensity is taken on the horizontal axis and the output value is taken on the vertical axis.

Explanation of symbols

1,2 ... delayed luminescence measuring device (optical measurement device), 24 ... storage unit, 23 ... arithmetic unit, 82 ... arithmetic unit, 83 ... storage _{unit, P, P 1, P 2} , P 3, R ... delayed luminescence detection (Multiplier type photodetector), L1, L2, L3... Reference light (input light).

Claims (7)

An optical measurement device that measures light from a measurement object,
A plurality of multiplication type photodetectors that receive light and output an electrical signal according to an applied voltage;
Output of three kinds of output values output from the photodetector according to the input of the input light and the light intensity change rate of at least three kinds of input light included in a predetermined light intensity range with different light intensities A storage unit that stores an applied voltage value set so that a relative ratio with a change rate is constant within a predetermined range, in association with each of the plurality of photodetectors;
A calculation unit that corrects the output value so that an output characteristic in a state where the applied voltage value is applied to the photodetector approximates a predetermined reference output characteristic;
An optical measuring device comprising:   The light detection apparatus according to claim 1, wherein the relative ratio is set so as to approximate between the plurality of light detectors. The storage unit corresponds to each of the plurality of photodetectors with a correction constant set so that an output characteristic in a state where the applied voltage value is applied to the photodetector approximates the reference output characteristic. And remember more,
The light detection device according to claim 1, wherein the calculation unit corrects the output values of the plurality of light detectors based on the correction constant stored in the storage unit. The three types of the input light are output in the order of the first intensity L1, the second intensity L2, and the third intensity L3 from the lowest, and the three types output from the photodetector by the input of the input light. Are set as the first output value C1, the second output value C2, and the third output value C3 in order from the lowest.
The light intensity change rate is Log (La / Lb) (a = 1or2or3, b = 1or2or3, a ≠ b),
The output change rate is Log (Ca / Cb) (a = 1or2or3, b = 1or2or3, a ≠ b),
2. The applied voltage value is set so that a relative ratio Nab between the light intensity change rate and the output change rate shown in the following equation is constant in the predetermined range. The optical measuring device as described in any one of -3.
Nab = {Log (Ca / Cb) / Log (La / Lb)} A plurality of measurement units each including a first unit to which the photodetector is attached and a second unit to which a light source for irradiating a measurement target with excitation light is attached;
The optical measurement apparatus according to claim 1, wherein the first unit is detachably attached to the second unit. In a calibration method for an optical measurement device comprising a plurality of multiplication type photodetectors that receive light and convert it into an electrical signal,
Applying an initial voltage to each photodetector;
Inputting at least three types of input light having different light intensities and included in a predetermined light intensity range to the photodetector;
Whether or not the relative ratio between the light intensity change rates of the three types of input light and the output change rates of the three types of output values output from the photodetector by the input of the input light is constant within a predetermined range. Determining
When the relative ratio between the light intensity change rate and the output change rate is not constant within the predetermined range, the voltage applied to the photodetector is adjusted so as to be constant within the predetermined range. Setting an applied voltage value;
A method for adjusting an optical measuring device comprising: Applying the applied voltage value corresponding to each of the plurality of photodetectors to each of the plurality of photodetectors;
Inputting reference input light to the plurality of photodetectors applied with the applied voltage value;
Calculating a correction constant for approximating output characteristics of output values output from the plurality of photodetectors by the input of the reference input light to predetermined reference output characteristics;
The method of adjusting an optical measurement device according to claim 6, further comprising:

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