Method for calibrating temperature measured by concentration measuring device, and concentration measuring device

Abstract

To provide a concentration measuring device that measures the concentration of a sample by absorptiometry, which is capable of performing temperature measurement in a shorter time than before. a temperature calibration unit that acquires difference information between the measured temperature of the sample and the measured temperature of the calibration sample, and a temperature calibration unit that acquires difference information between the measured temperature of the sample and the measured temperature of the calibration sample, and a temperature calibration unit that acquires difference information between the measured temperature of the sample to be measured and the measured temperature of the environmental temperature, and calibrates the measured temperature of the sample to be measured using calibration temperature information based on the second correlation information for the measured transmittance of the calibration sample by the concentration measuring device.

Description

[Technical field]

[0001] The present invention relates to a concentration measuring device that performs concentration measurement based on measuring the temperature and transmittance or absorbance of a sample having a correlation between the temperature, transmittance or absorbance, and concentration, and a method for calibrating the measurement temperature in the concentration measuring device. [Background technology]

[0002] In medical settings, medical instruments used in surgeries and other procedures are cleaned, sterilized, and reused, but when cleaning endoscopes, for the safety of patients, it is stipulated that visible dirt must be wiped off and then the instruments must be cleaned with a prescribed concentration of high-level disinfectant (Reference: "Guidelines for Standardization of Cleaning and Disinfection of Digestive Endoscopes" issued by the Japan Society for Gastroenterological Endoscopy and the Japanese Association of Infectious Diseases). Since the disinfectants used for cleaning are relatively expensive, they are generally used repeatedly a certain number of times or for a certain period of time, and when they are used, their concentration is measured to ensure that they have the specified concentration. Patent Document 1 discloses a technique relating to an apparatus for measuring the concentration of such a disinfectant by absorptiometry. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-69969 A Summary of the Invention [Problem to be solved by the invention]

[0004] Disinfectants such as glutaral and phthalaral aqueous solutions have a correlation between temperature, transmittance (or absorbance), and concentration. Therefore, in order to measure the concentration based on transmittance using absorptiometry, it is necessary to measure the temperature as well (or to measure under specified temperature conditions). Here, the concentration measurement of the disinfectant in the concentration measuring device using absorptiometry is performed on the disinfectant (sample) contained in an optical cell, as described in Patent Document 1, but it is not necessarily easy to accurately measure the temperature of the liquid in such a cell. In short, it is conceivable to measure the temperature by directly contacting a contact-type temperature sensor such as a thermocouple with the disinfectant in the optical cell, but in the case of the contact type, if there is a temperature difference between the disinfectant and the temperature sensor, there is a problem that it will be affected by the heat capacity of the temperature sensor itself. Based on the viewpoints of workability and not wasting disinfectant, the amount of disinfectant in the optical cell is about several cc, and there are cases where the effect of the temperature sensor contacting the optical cell cannot be ignored. To solve this problem, it may be possible to use a non-contact temperature sensor. However, if a non-contact radiation sensor is used, the radiation temperature from the wall of the optical cell is measured. If there is a temperature difference between the optical cell and the disinfectant, the temperature of the disinfectant may not be measured correctly. Conventionally, in order to prevent or reduce these problems, concentration measurements (temperature measurements for this purpose) are performed after waiting until there is no temperature difference between the disinfectant and the concentration measurement device (such as an optical cell) (by leaving them at ambient temperature to achieve thermal equilibrium). However, such an operation is cumbersome, and there is a demand for concentration measurement to be performed in a shorter time.

[0005] In view of the above, an object of the present invention is to provide a concentration measuring device (and a method for calibrating the measured temperature) that measures the concentration of a sample by absorptiometry and that is capable of performing temperature measurement relatively accurately and in a short period of time. [Means for solving the problem]

[0006] (Configuration 1) A method for calibrating a measured temperature in a concentration measuring device that performs concentration measurement based on measuring the temperature and transmittance or absorbance of a sample having a correlation between the temperature, transmittance or absorbance, and concentration, comprising the steps of: acquiring first correlation information between the temperature and transmittance or absorbance based on a sample having a known concentration; measuring values ​​over time for the temperature, transmittance or absorbance, and environmental temperature of the sample having a known concentration using a concentration measuring device that includes a sample temperature sensor, an optical sensor, and an environmental temperature sensor; and acquiring first difference information between the measured environmental temperature and the measured sample temperature, and the transmittance or absorbance. A method for calibrating the measured temperature of a concentration measuring device, comprising: a step of acquiring second correlation information between a theoretical temperature based on the first correlation information for a measured value of light intensity and second difference information between the measured value of the temperature of a sample whose concentration is known; a step of acquiring difference information between the measured value of the temperature of the sample by the sample temperature sensor and the measured value of the environmental temperature by the environmental temperature sensor in measuring the concentration of a sample whose concentration is unknown, and acquiring calibration temperature information based on the second correlation information for the difference information; and a step of calibrating the measured value of the temperature of the sample using the calibration temperature information.

[0007] (Configuration 2) A method for calibrating the measured temperature of a concentration measuring device described in configuration 1, wherein, in acquiring the second correlation information, positive second correlation information and negative second correlation information are acquired depending on whether the difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of a sample whose concentration is known is positive or negative, and the calibration temperature information is acquired based on either the positive second correlation information or the negative second correlation information depending on whether the difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of a sample whose concentration is unknown is positive or negative.

[0008] (Configuration 3) A method for calibrating the measured temperature of a concentration measuring device described in configuration 1 or 2, wherein an error is detected when the absolute value of the difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of a sample whose concentration is unknown is greater than the absolute value of the maximum value of the difference between the measured environmental temperature and the measured sample temperature when measuring a sample whose concentration is known.

[0009] (Configuration 4) a concentration measuring device that performs concentration measurement based on measurement of temperature and transmittance or absorbance for a sample having a correlation between temperature, transmittance or absorbance, and concentration, the concentration measuring device comprising: a sample temperature sensor for measuring the temperature of the sample; an optical sensor for measuring the transmittance or absorbance of the sample; an environmental temperature sensor for measuring environmental temperature; a memory unit that stores first difference information between the environmental temperature measurement value by the concentration measuring device and the temperature measurement value of a calibration sample, and second correlation information between a theoretical temperature based on the first correlation information between the temperature and transmittance or absorbance of the calibration sample for the measurement value of the transmittance or absorbance of the calibration sample by the concentration measuring device and the measurement value of the temperature of the calibration sample; and a temperature calibration unit that acquires difference information between the sample temperature measurement value by the sample temperature sensor and the environmental temperature measurement value by the environmental temperature sensor, and calibrates the measurement value by the sample temperature sensor using calibration temperature information based on the second correlation information for the difference information; A concentration measuring device comprising:

[0010] (Configuration 5) The concentration measuring device of configuration 4, wherein the second correlation information includes positive second correlation information and negative second correlation information corresponding to the positive or negative difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of the calibration sample, and the calibration temperature information is acquired based on either the positive second correlation information or the negative second correlation information corresponding to the positive or negative difference between the measured environmental temperature by the environmental temperature sensor and the measured sample temperature by the sample temperature sensor.

[0011] (Configuration 6) A concentration measuring device according to configuration 4 or 5, wherein error processing is performed when the absolute value of the difference between the environmental temperature measured by the environmental temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold value.

[0012] (Configuration 7) A concentration measuring device according to configuration 4 or 5, wherein, when the absolute value of the difference between the environmental temperature measured by the environmental temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold, a process of waiting until the difference becomes equal to or less than the threshold is performed. Effect of the Invention

[0013] According to the present invention, it is possible to provide a concentration measuring device (and a method of calibrating the measured temperature) that measures the concentration of a sample by absorptiometry and that is capable of performing temperature measurement relatively accurately and in a short time. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing an outline of a configuration of a concentration measuring device according to an embodiment of the present invention; [Diagram 2] 1 is a flowchart showing an outline of a concentration measurement method (mainly a method for calibrating a measurement temperature) according to an embodiment of the present invention; [Diagram 3] Graph showing an example of a correlation between temperature and transmittance (first correlation information) created based on a disinfectant solution with a known concentration [Figure 4] An example of a graph showing the difference between the temperature of a disinfectant solution with a known concentration and the environmental temperature measured over time using a concentration measuring device, Tsub1. [Diagram 5] An example in which the transmittance of a disinfectant with a known concentration is measured over time using a concentration measuring device, and the measured transmittance is converted to a theoretical temperature based on the first correlation information and graphed. [Figure 6] An example of a graph showing the temperature difference between the theoretical temperature and Tsub2 for a disinfectant solution with a known concentration. [Figure 7] Graph showing an example of the correlation between Tsub1 and Tsub2 (second correlation information) [Figure 8] A graph in which the approximation formula (second correlation information) of the graph in Figure 7 is further plotted. [Figure 9] Graph showing results of a demonstration experiment of the concentration measurement device of the embodiment [Figure 10]11 is a flowchart showing another example of a part of the processing operation of the concentration measurement method (mainly the method of calibrating the measurement temperature) according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Note that the following embodiment is one form for embodying the present invention, and is not intended to limit the scope of the present invention.

[0016] FIG. 1 is a block diagram showing an outline of the configuration of a concentration measuring device according to an embodiment of the present invention. The concentration measuring device 1 of the present embodiment is a concentration measuring device that measures the concentration of a disinfectant such as a glutaral aqueous solution or a phthalaral aqueous solution, which has a correlation between the temperature, transmittance or absorbance, and concentration, based on the measurement of the temperature and the transmittance or absorbance, an optical cell OC for containing a disinfectant; a radiation temperature sensor 13 that functions as both a sample temperature sensor for measuring the temperature of the disinfectant and an environmental temperature sensor for measuring the environmental temperature; A light emitting unit 141 and a light receiving unit 142 which are optical sensors for measuring the transmittance or absorbance of a disinfectant; A storage unit 12 in which various data and programs necessary for the operation of the device are permanently or temporarily stored; an input unit 15 having input means such as operation buttons and serving as a user interface; an output unit 16 that is provided with output means such as a screen and an indicator and serves as a user interface; A control and calculation unit 11 that controls each part of the device and performs various calculation processes and also functions as a temperature calibration unit as described below; It is equipped with: With regard to the above reference to "transmittance or absorbance," absorbance is the logarithm of the reciprocal of transmittance, and the difference between transmittance and absorbance does not bring about a conceptual difference in the application of the present invention (for example, when treated as absorbance, a conversion based on the above relational expression can be performed), and therefore, hereinafter, it will be simply referred to as "transmittance."

[0017] The optical cell OC is a container made of a material that transmits the light emitted by the light emitting portion 141, and contains about several ccs of disinfectant. The optical cell OC is detachable from the concentration measuring device 1, and is basically a single-use (disposable) member.

[0018] The radiation temperature sensor 13 is provided at a position facing the area of ​​the optical cell OC attached to the concentration measuring device 1 where the disinfectant is contained, and measures the temperature of the sample (disinfectant) in a non-contact manner. The radiation temperature sensor is for measuring the temperature of the disinfectant, but since the temperature is measured based on infrared rays emitted from the surface of the optical cell OC, the surface temperature of the wall of the optical cell OC is actually measured. Therefore, if there is a temperature difference between the optical cell OC and the disinfectant due to, for example, differences in the environmental temperatures between the storage location of the concentration measuring device 1 or the optical cell OC and the installation location of the endoscope cleaning device containing the disinfectant, the actual liquid temperature of the disinfectant may not be measured correctly. In contrast, according to the concentration measuring device 1 and the concentration measuring method (mainly the method of calibrating the measured temperature) of this embodiment, the measured value of the radiation temperature sensor 13 can be calibrated as described below, thereby making it possible to measure the liquid temperature of the disinfectant more accurately. In this embodiment, the reference temperature sensor provided in the radiation temperature sensor 13 is used as the environmental temperature sensor, and therefore the radiation temperature sensor 13 functions as both a sample temperature sensor and an environmental temperature sensor. Hereinafter, for convenience, the sample temperature sensor will be referred to as the "sample temperature sensor 131" and the environmental temperature sensor will be referred to as the "environmental temperature sensor 132." The radiation temperature sensor 13 is connected to the control and calculation unit 11, and the reading of the sensor value and the like are controlled by the control and calculation unit 11.

[0019] The light-emitting unit 141 and the light-receiving unit 142, which are optical sensors for measuring the transmittance of the disinfectant, are arranged so that the optical axis of the light-emitting unit 141 passes through the disinfectant in the optical cell OC and so that the light-receiving unit 142 can receive the light that has passed through the disinfectant. Here, an example is taken in which the light-emitting unit 141 is arranged to face one side of the optical cell OC and the light-receiving unit 142 is arranged to face the opposite side, but the light-emitting unit 141 and the light-receiving unit 142 may be arranged in any manner as long as they are configured to receive light that has passed through the disinfectant. The light emitting section 141 is connected to the control and calculation section 11 via a driver circuit 1411 that drives light emission, and the timing of light emission and the like are controlled by the control and calculation section 11. The light receiving unit 142 is also connected to the control and calculation unit 11, and the control of reading the sensor value, the calculation process of the transmittance based on the sensor value, and the like are performed by the control and calculation unit 11.

[0020] The user interface, that is, the input unit 15 and the output unit 16, can use any input interface such as a button, a touch panel, or a voice input unit, or any output interface such as a visual display device such as an indicator or a display screen, or an auditory output unit such as a speaker. The input / output unit is not limited to an interface for a user, but may be any input / output unit for inputting and outputting information between the device and another device.

[0021] The storage unit 12 may be any storage device capable of storing various data, programs, etc. required for the operation of the device. The storage unit 12 stores a program for executing the process described below and data required for executing the temperature calibration process described below. One of the pieces of data is "second correlation information between first difference information, which is the difference between the measured environmental temperature by the concentration measuring device 1 and the measured temperature of the calibration sample (disinfectant solution with a known concentration), and second difference information, which is the difference between the theoretical temperature and the temperature of the calibration sample based on first correlation information between the temperature and transmittance of the calibration sample for the measured transmittance of the calibration sample by the concentration measuring device 1." This will be described in detail below.

[0022] The control / calculation unit 11 controls each part of the apparatus and performs various calculation processes, and is configured using any semiconductor device that performs calculation processes and is equipped with a CPU (Central Processing Unit), such as a microcomputer. The control and calculation unit 11 also functions as a temperature calibration unit for performing the process described below of "obtaining difference information between the disinfectant temperature measurement value by the sample temperature sensor 131 and the environmental temperature measurement value by the environmental temperature sensor 132, and calibrating the measurement value by the sample temperature sensor 131 using calibration temperature information based on second correlation information for the difference information." It also functions as a concentration calculation unit that calculates the concentration of the disinfectant based on the temperature information of the disinfectant after calibration and the transmittance information of the disinfectant. Although not shown in the figure, it goes without saying that the control / calculation unit 11 is connected to each unit via an A / D conversion circuit, various filter circuits, etc. as necessary (suitably providing circuits to make the signals suitable for input / output to the control / calculation unit 11). Here, the temperature calibration unit, concentration calculation unit, etc. are shown as an example implemented as software on a general-purpose device (configured by a program running on the control / calculation unit 11), but some or all of them may also be configured as hardware (for example, by a dedicated IC, etc.).

[0023] Next, the concentration measurement method (mainly the method of calibrating the measurement temperature) of this embodiment will be described with reference to FIG. 2 is a flow chart showing an outline of the concentration measurement method (mainly the method of calibrating the measurement temperature) of this embodiment. Flows 1 to 5 are the calibration process (setting of parameters for temperature calibration) of the radiation temperature sensor 13 performed for each concentration measurement device 1 in the device manufacturing factory, and flows 6 to 8 are the process of measuring concentration in the concentration measurement device 1 (calibration of the measurement temperature for this purpose).

[0024] In flow 1, first correlation information between temperature and transmittance is obtained based on a disinfectant solution (calibration sample) of known concentration. Specifically, disinfectants of different concentrations, the concentrations of which are measured by HPLC (high performance liquid chromatography), are prepared, and the transmittance of each disinfectant of each concentration is measured under constant temperature conditions, such as 10, 15, 20, 25, 30, and 35°C, for example, by holding the disinfectant in a thermostatic bath for a certain period of time. Figure 3 shows an example of a graph of the correlation between the temperature and transmittance of the disinfectant (calibration sample) obtained in this way. The range of the concentration of the disinfectant to be measured may be determined based on the concentration during actual use. In this case, the measurement was performed in the range of 0.55 to 0.20%, taking into consideration that the concentration of the target disinfectant (product) when new is 0.55% and the limit concentration for use is 0.3%.

[0025] Next, we determine the approximate equation for the graph in Figure 3 (a function of concentration N, temperature T, and transmittance k). The concentration N is calculated using the temperature T and the transmittance k according to the following formula 1. (Formula 1) N = iT 2 k 2 +hTk 2 +gk 2 +fT 2 k+eTk+dk+cT 2 +bT+a Note that a to i are coefficients. In the following equation 2, which is a transformation of equation 1, A=iT 2 +hT+g, B=fT 2 +eT+d, C=cT 2 +bT+a, we get a quadratic function of k (Equation 3). (Formula 2) N = (iT 2 +hT+g)k 2 +(fT 2 +eT+d)k+(cT 2 +bT+a) (Formula 3) N=Ak 2 +Bk+C In formula 3, A, B, and C are calculated by the least squares method, and the coefficients a to i are calculated from the calculated A to C (quadratic functions of T) by the least squares method. This gives the coefficients of Equation 1 that approximate the graph in FIG. Note that both the information on the graphed state of FIG. 3 (or information for that purpose) and the information as an approximation formula obtained based on this correspond to the "first correlation information". The calculation process of the "first correlation information" is performed on an information processing device such as a PC having an application for calculating the above approximation formula (a device separate from the concentration measuring device 1), but it may also be configured to be executable on the concentration measuring device 1.

[0026] In flow 2, the concentration measuring device 1 to be calibrated is used to measure the temperature, transmittance, and environmental temperature of a calibration sample (a disinfectant solution with a known concentration) over time. More specifically, a concentration measuring device 1 (optical cell OC) that is temperature-controlled at the environmental (ambient) temperature (e.g., 15°C) and a calibration sample that is temperature-controlled at a different temperature (e.g., 30°C) are prepared, and the temperature, transmittance, and environmental temperature of the calibration sample are acquired over time using the concentration measuring device 1. Data is acquired as the optical cell OC, which has a different temperature, and the calibration sample placed therein reach thermal equilibrium. Note that this measurement over time is preferably continued until a state that can be considered as thermal equilibrium is reached (a state in which there is no temperature difference between the environmental temperature and the liquid temperature). Then, the first difference information T sub1 (Similar to the above, this calculation process uses an information processing device such as an external device, such as a PC, but may also be performed by the concentration measuring device 1). The above process of flow 2 is performed under conditions where the environmental temperature (temperature of the concentration measuring device 1 (optical cell OC)) and the temperature of the calibration sample are different as described above, and the high and low temperatures are reversed (for example, the environmental temperature is 30°C and the temperature of the calibration sample is 15°C, as opposed to the above example). The environmental temperature and the temperature of the calibration sample should be set to be close to the maximum temperature difference that can be assumed in the actual environment in which the concentration measuring device 1 is used. Here, the following conditions are assumed as examples: 1. Environmental temperature 15°C, calibration sample temperature 30°C (FIG. 4(a)), 2. Environmental temperature 30°C, calibration sample temperature 15°C (FIG. 4(b)). Since a slight difference in the concentration of the disinfectant does not have a significant effect on the behavior of thermal equilibrium, the concentration of the calibration sample for acquiring data on the progress of thermal equilibrium may be any concentration (for example, any of the concentration ranges used in flow 1), but here, a disinfectant of 0.3%, which is the maximum concentration for use, is used. Figure 4 shows an example of the data obtained in Flow 2. object is the temperature of the calibration sample acquired by the sample temperature sensor 131, T PTAT is the environmental temperature acquired by the environmental temperature sensor 132, T sub1 is the difference between the two. Figure 4(a) shows the case where the liquid temperature is higher than the environmental temperature, and Figure 4(b) shows the case where the liquid temperature is lower than the environmental temperature. In this case, T sub1 T PTAT From T object The example shows a case where T object From T PTAT (In the processing described below, the sign may be reversed as necessary, and the difference between the sign and the positive sign does not result in a difference in concept.)

[0027] In flow 3, a process is performed to calculate a theoretical temperature based on the first correlation information for the measured values ​​of the transmittance of the calibration sample measured over time using the concentration measuring device 1 in flow 2. That is, in the first correlation information, Equation 1, the concentration N (known) and transmittance k (measured over time) of the calibration sample are used to calculate the temperature T (theoretical temperature T ref ) is calculated. Figure 5 shows the calculated theoretical temperature T ref An example of a graph is shown in Fig. 5. (a) shows the case where the liquid temperature is higher than the ambient temperature (when the liquid temperature gradually drops due to thermal equilibrium), and (b) shows the case where the liquid temperature is lower than the ambient temperature (when the liquid temperature gradually rises due to thermal equilibrium). The process of flow 3 is also performed on an information processing device such as a PC (a device separate from the concentration measuring device 1), but may be configured to be executed on the concentration measuring device 1.

[0028] In flow 4, the theoretical temperature T ref and the temperature T of the calibration sample acquired by the sample temperature sensor 131. object The second difference information T sub2 This second difference information T sub2 and the first difference information T sub1 and obtain second correlation information between. Figure 6 shows the theoretical temperature T ref and the temperature of the calibration sample T object and the second difference information T sub2 6(a) shows the case where the liquid temperature is higher than the environmental temperature, and FIG. 6(b) shows the case where the liquid temperature is lower than the environmental temperature. FIG. 7 shows the second difference information T sub2 is the Y axis, and the first difference information T sub1 7A shows a graph (second correlation information) with the X-axis being the liquid temperature higher than the environmental temperature (negative second correlation information), and FIG. 7B shows a graph (second correlation information) in which the liquid temperature is lower than the environmental temperature (positive second correlation information). sub2 is the Y axis, and the first difference information T sub1 is used as the X-axis as an example, but the second difference information T sub2 is the X-axis, and the first difference information T sub1 may be used as the Y-axis (there is no conceptual difference between the two).

[0029] In flow 5, the graph in FIG. sub2 and the first difference information Tsub1 Find an approximation for (a function of ). In this embodiment, exponential approximation (calculation of coefficients a1, b1, and c1) is performed based on equation (4). (Formula 4) T sub2 =a1·e (b1·Tsub1) +c1 The obtained approximation formula is shown in graph form in Fig. 8. Fig. 8(a) shows the case where the liquid temperature is higher than the environmental temperature (negative second correlation information), and Fig. 8(b) shows the case where the liquid temperature is lower than the environmental temperature (positive second correlation information). That is, the coefficients a1, b1, and c1 corresponding to the negative second correlation information and the coefficients a1, b1, and c1 corresponding to the positive second correlation information are obtained. Note that both the information in the graphed state of FIG. 8 (or information for that purpose) and the information as an approximation formula obtained based on this correspond to the "second correlation information". The process of obtaining the second correlation information in flows 4 and 5 is also performed on an information processing device such as a PC (a device separate from the concentration measuring device 1), but may be configured to be executed on the concentration measuring device 1.

[0030] The above processes from flow 1 to flow 5 are performed for each concentration measuring device 1 in the manufacturing plant, and the parameters of coefficients a1, b1, c1 (coefficients a1, b1, c1 corresponding to negative second correlation information and coefficients a1, b1, c1 corresponding to positive second correlation information) constituting the "second correlation information" corresponding to each concentration measuring device 1 are set (stored in memory unit 12) for each concentration measuring device 1, thereby performing a calibration process (setting of parameters for temperature calibration) of the radiation temperature sensor 13.

[0031] The concentration measurement of the disinfectant using the concentration measuring device 1 is performed by the processes of flows 6 to 8. Note that the concentration calculation process (flow 8) itself can use a conventional method as is, so the explanation here is omitted and the explanation will be focused on the calibration of the measurement temperature of the disinfectant, which is necessary for the concentration calculation.

[0032] Measurement of the concentration of a disinfectant (a sample with an unknown concentration) using the concentration measuring device 1 is performed by setting an optical cell OC in the device and pouring disinfectant into it, and then measuring the temperature of the disinfectant using the sample temperature sensor 131, measuring the environmental temperature using the environmental temperature sensor 132, and measuring the transmittance of the disinfectant using the light-emitting unit 141 and the light-receiving unit 142. In flow 6, it is determined whether the value obtained by subtracting the disinfectant temperature measured by the sample temperature sensor 131 from the environmental temperature measured by the environmental temperature sensor 132 is positive or negative. If the result of the determination is negative, the processes of steps 7-1 and 8-1 are executed, and if the result is positive, the processes of steps 7-2 and 8-2 are executed. Note that, although 0 is treated as a negative process here, 0 may be treated as a positive process.

[0033] In flow 7-1, the value (T sub1 ) into the approximation formula (4) (the negative second correlation information corresponding to FIG. 8(a)) to obtain the temperature difference information (T sub2 ) is calculated by the control and calculation unit 11. Then, the temperature difference information (T sub2 ) is used (added) by the control and calculation unit 11 to calibrate the measured value of the disinfectant temperature by the sample temperature sensor 131. In flow 8-1, the control and calculation unit 11 performs a process of calculating the concentration of the disinfectant using the temperature information of the disinfectant calibrated in flow 7-1 and the measured value of the transmittance of the disinfectant. In addition, when the result of the judgment in flow 6 is positive, the processing in flows 7-2 and 8-2 is the same as the processing in flows 7-1 and 8-1, except that "positive second correlation information corresponding to FIG. 8(b)" is used instead of "negative second correlation information corresponding to FIG. 8(a)", and therefore the explanation will be omitted.

[0034] FIG. 9 shows the results of measuring the concentration of a disinfectant solution having a concentration of 0.3% using the concentration measuring device 1 (results of a demonstration experiment). In order to show the effect of temperature calibration by the concentration measuring device 1, the figures show the concentration calculated at the temperature before calibration (i.e., using the measured value of the sample temperature sensor 131 as is) and the concentration calculated at the temperature after calibration. Fig. 9(a) shows the case where the liquid temperature is higher than the environmental temperature (liquid temperature at the start of measurement set to about 25°C, environmental temperature set to about 15°C), and Fig. 9(b) shows the case where the liquid temperature is lower than the environmental temperature (liquid temperature at the start of measurement set to about 20°C, environmental temperature set to about 30°C). In the graph, the dotted line indicates the range of ±0.01 for a concentration of 0.3%, which is within the standard. As shown in the figure, the concentration based on the pre-calibration temperature is outside the range of ±0.01 for the disinfectant solution, which is originally at a concentration of 0.3%, for just under 20 seconds from the start of measurement when the liquid temperature at the start of measurement is set to about 25°C and the ambient temperature is set to about 15°C, and for about 45 seconds from the start of measurement when the liquid temperature at the start of measurement is set to about 20°C and the ambient temperature is set to about 30°C. In other words, in the past, it was necessary to wait at least that long before measuring (since it is not clear exactly how long one should actually wait, a waiting time of at least 60 seconds is necessary to be on the safe side). In contrast, when the temperature calibration of this embodiment is used, concentration measurements within the specifications are obtained approximately 5 seconds after the start of measurement when the liquid temperature at the start of measurement is set to approximately 25°C and the ambient temperature is set to approximately 15°C, and when the liquid temperature at the start of measurement is set to approximately 20°C and the ambient temperature is set to approximately 30°C, so concentration measurements can be performed in a short time. Immediately after the disinfectant is injected into the optical cell, the measured value may not be stable due to the movement of the liquid caused by the injection, the generation of air bubbles, etc. (The data discrepancy immediately after the start in FIG. 9(b) is also likely to be largely due to this influence.) Therefore, a predetermined waiting time (for example, about 10 to 15 seconds) may be provided until the liquid in the optical cell settles.

[0035] As described above, the concentration measuring device 1 and the method for calibrating the measured temperature of the present embodiment make it possible to accurately measure (calibrate) the temperature of the disinfectant even under conditions where there is a temperature difference between the environmental temperature and the temperature of the disinfectant. Therefore, it is possible to shorten or eliminate the waiting time required until the environmental temperature and the temperature of the disinfectant become the same, which was previously required, and concentration measurement can be performed in a short time. Although it is problematic to accurately measure the temperature of the disinfectant when obtaining a calibration curve for the calibration, this embodiment solves this problem by utilizing the correlation between the temperature of the disinfectant and the transmittance and obtaining the liquid temperature (theoretical temperature) based on the transmittance. This makes it possible to obtain the correlation (i.e., the calibration curve for calibration) between the apparent temperature of the disinfectant (cell wall temperature) obtained by the sensor and the value (theoretical temperature) that estimates the actual temperature of the disinfectant.

[0036] In this embodiment, positive second correlation information and negative second correlation information are acquired separately depending on whether the difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of the calibration sample is positive or negative. This is because different trends were observed in the direction of decreasing liquid temperature and the direction of increasing liquid temperature, and so these are treated separately (to improve accuracy). This trend is thought to be influenced by heat, etc., emitted by the concentration measuring device, which is an electronic device. In other words, it is thought that the heat emitted by the light-emitting unit and other electronic components during operation tends to bias the direction of increasing liquid temperature, resulting in different trends (not symmetrical) in the direction of decreasing liquid temperature and the direction of increasing liquid temperature. Therefore, in an apparatus configured so that the effects of heat and the like of electronic components can be ignored, calibration may be performed using only one "second correlation information" without separating it into positive second correlation information and negative second correlation information. In addition, by introducing a correction value that evaluates the "bias due to the influence of heat, etc., of electronic components," calibration may be performed using only one "second correlation information" (the above bias amount is further calibrated using the correction value).

[0037] When there is no temperature difference between the environmental temperature and the disinfectant temperature (i.e., T sub1 is close to 0), the calibration process described above is not necessarily required, so T sub1 If is close to 0 (equal to or less than a predetermined value), the concentration may be calculated based on the measurement value of the sample temperature sensor 131 without performing the temperature calibration process of step 7.

[0038] In addition, if the difference (absolute value) between the measured environmental temperature and the measured sample temperature when measuring the concentration of a sample with an unknown concentration is greater than the maximum value (absolute value) of the difference between the measured environmental temperature and the measured sample temperature when measuring a calibration sample (sample with a known concentration), error processing may be performed, such as outputting error information to output unit 16. This is outside the range of calibration data and is treated as an error. Instead of treating this as an error, a process may be performed in which the temperature difference between the ambient temperature and the disinfectant temperature becomes equal to or less than the maximum value of the difference between the measured ambient temperature and the measured sample temperature when measuring the calibration sample, due to thermal equilibrium. FIG. 10 shows an example of this process. The process of FIG. 10 is a process replacing the part of flow 6 in FIG. 2. As a prerequisite for this process, sub1 The absolute values ​​of the maximum values ​​(positive and negative, respectively) of are set in the concentration measuring device 1 (storage unit 12) as thresholds 1 and 2. For example, in the process of flow 2, if the environmental temperature is 16°C and the calibration sample temperature is 29°C, threshold 1 is set to 13°C, and if the environmental temperature is 31°C and the calibration sample temperature is 15°C, threshold 2 is set to 16°C. In step 901, a value (T sub1 ) is positive or negative. If the result of the determination is negative, the processes of steps 902 and 903 are executed, and if the result is positive, the processes of steps 904 and 905 are executed. Note that although 0 is treated as a negative process, 0 may be treated as a positive process. Also, as described above, if the result is 0, the temperature calibration process may be skipped. In step 902, T sub1 It is determined whether the absolute value of T exceeds the threshold 1, and if it does, a message such as "Waiting until the liquid temperature reaches a measurement-enabling condition (or simply "Measuring")" is displayed on the output unit 16 (step 903). sub1 The loop process of steps 902 and 903 is repeated until the absolute value of becomes equal to or smaller than threshold value 1. In the determination of step 902, T sub1 If the absolute value of is equal to or smaller than threshold value 1, the process proceeds to flow 7-1 in FIG. 2, where a calibration process is performed. When the result of the determination in step 901 is positive, the processes in steps 904 and 905 are the same as those in steps 902 and 903 except that threshold value 2 is used instead of threshold value 1, and therefore a description thereof will be omitted.

[0039] In the embodiment, disinfectants such as a glutaral aqueous solution or a phthalaral aqueous solution are used as examples of the concentration to be measured, but the present invention is not limited to this, and the concept of the present invention can be applied to any sample having a correlation between temperature, transmittance or absorbance, and concentration.

[0040] In the embodiment, a radiation temperature sensor, which is a non-contact temperature sensor, is used as an example of the temperature sensor, but the present invention is not limited to this. For example, the concept of the present invention can be applied to a configuration in which the temperature of the optical cell is measured by any temperature sensor, such as a contact temperature sensor. In addition, an example is given in which a reference temperature sensor provided in a radiation temperature sensor is used as an environmental temperature sensor for measuring the environmental temperature, but the present invention is not limited to this, and any temperature sensor capable of measuring the environmental temperature may be provided separately. [Explanation of symbols]

[0041] 1...Concentration measuring device 11...Control / calculation section (temperature calibration section) 12...Storage section 13...Radiation temperature sensor (sample temperature sensor, environmental temperature sensor) 141...Light emitting unit (optical sensor) 142...Light receiving unit (optical sensor)

Claims

1. 1. A method for calibrating a measured temperature in a concentration measuring device that performs concentration measurement based on measurement of temperature and transmittance or absorbance for a sample having a correlation between temperature, transmittance or absorbance, and concentration, comprising: Obtaining a first correlation information between temperature and transmittance or absorbance based on a sample of known concentration; measuring, over time, values ​​related to the temperature, transmittance or absorbance, and environmental temperature of a sample having a known concentration by a concentration measuring device including a sample temperature sensor, an optical sensor, and an environmental temperature sensor; acquiring second correlation information between first difference information between the measured value of the environmental temperature and the measured value of the temperature of the sample, and second difference information between a theoretical temperature based on the first correlation information for the measured value of the transmittance or absorbance and the measured value of the temperature of the sample having a known concentration; In measuring the temperature of a sample having an unknown concentration, a step of acquiring difference information between a measured value of the temperature of the sample by the sample temperature sensor and a measured value of the environmental temperature by the environmental temperature sensor, and acquiring calibration temperature information based on the second correlation information for the difference information; calibrating a measurement of the temperature of the specimen with the calibration temperature information; A method for calibrating a measured temperature of a concentration measuring device, comprising:

2. In acquiring the second correlation information, positive second correlation information and negative second correlation information are acquired depending on whether a difference between a measured value of the environmental temperature and a measured value of the sample temperature when measuring the concentration of the sample having a known concentration is positive or negative, 2. The method for calibrating the measured temperature of a concentration measuring device according to claim 1, further comprising acquiring the calibration temperature information based on either the positive second correlation information or the negative second correlation information in response to a positive or negative difference between the measured environmental temperature and the measured sample temperature when measuring the sample whose concentration is unknown.

3. 3. A method for calibrating the measured temperature of a concentration measuring device according to claim 1 or 2, wherein an error is detected when the absolute value of the difference between the measured environmental temperature and the measured sample temperature when measuring the concentration of a sample whose concentration is unknown is greater than the absolute value of the maximum value of the difference between the measured environmental temperature and the measured sample temperature when measuring a sample whose concentration is known.

4. A concentration measurement device for performing concentration measurement based on measurement of temperature and transmittance or absorbance of a sample having a correlation between temperature, transmittance or absorbance, comprising: a sample temperature sensor for measuring the temperature of the sample; an optical sensor for measuring the transmittance or absorbance of a sample; an environmental temperature sensor for measuring an environmental temperature; a storage unit that stores first difference information between a measurement value of an environmental temperature and a measurement value of a temperature of a calibration sample obtained by the concentration measuring device, and second difference information between a theoretical temperature and the measurement value of the temperature of the calibration sample based on first correlation information between the temperature of the calibration sample and the transmittance or absorbance of the calibration sample for the measurement value of the transmittance or absorbance of the calibration sample obtained by the concentration measuring device; a temperature calibration unit that acquires difference information between the sample temperature measurement value obtained by the sample temperature sensor and the environmental temperature measurement value obtained by the environmental temperature sensor, and calibrates the measurement value obtained by the sample temperature sensor using calibration temperature information based on the second correlation information for the difference information; A concentration measuring device comprising:

5. the second correlation information includes positive second correlation information and negative second correlation information according to whether a difference between a measured value of the environmental temperature and a measured value of the sample temperature at the time of measuring the concentration of the calibration sample is positive or negative; 5. The concentration measuring device according to claim 4, wherein the calibration temperature information is acquired based on either the positive second correlation information or the negative second correlation information, corresponding to the positive or negative difference between the environmental temperature measurement value by the environmental temperature sensor and the sample temperature measurement value by the sample temperature sensor.

6. 6. The concentration measuring device according to claim 4, wherein an error process is performed when an absolute value of a difference between the environmental temperature measured by the environmental temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold value.

7. 6. The concentration measuring device according to claim 4, wherein, when the absolute value of the difference between the environmental temperature measured by the environmental temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold, a process of waiting until the difference falls below the threshold is performed.

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