Method for correcting measurement temperature of concentration measuring device and concentration measuring device

Abstract

A concentration measuring device capable of measuring a temperature in a shorter time than conventional devices by measuring a concentration of a sample by an absorbance method. A concentration measuring device (1) includes a sample temperature sensor (13) that measures a temperature of a sample; an optical sensor (141, 142) that measures a transmittance of the sample; an ambient temperature sensor (13) that measures an ambient temperature; a storage unit (12) that stores second correlation information between first difference information and second difference information, the first difference information being difference information between a measured value of the ambient temperature obtained by the concentration measuring device (1) and a measured value of a temperature of a calibration sample, the second difference information being difference information between a theoretical temperature and the measured value of the temperature of the calibration sample, the theoretical temperature being obtained based on first correlation information between the temperature and the transmittance of the calibration sample with respect to a measured value of the transmittance of the calibration sample obtained by the concentration measuring device (1); and a temperature correction unit (11) that acquires difference information between a measured value of a temperature of a measurement target sample and a measured value of the ambient temperature, and corrects the measured value of the temperature of the measurement target sample based on correction temperature information obtained based on the second correlation information with respect to the difference information.

Description

Technical Field

[0001] The present invention relates to a concentration measuring device for measuring the concentration of a sample having a correlation among temperature, transmittance or absorbance, or concentration, or a method for correcting the measured temperature in the concentration measuring device. The concentration measuring device measures the concentration of the sample based on the measurement of the temperature and transmittance or absorbance. Background Art

[0002] In medical settings, medical instruments used in surgeries, etc., are cleaned, sterilized, and reused. However, for patient safety, endoscopes are cleaned using a high-level disinfectant at a specified concentration after wiping off visible dirt (reference: "Guidelines for Standardization of Cleaning and Disinfection of Gastrointestinal Endoscopes" published by the Japanese Society of Gastroenterological Endoscopy and the Japanese Society of Infectious Diseases).

[0003] Disinfectants used for cleaning are relatively expensive, so they are usually used repeatedly a certain number of times or for a certain period of time. During use, concentration measurements are performed to confirm that the disinfectant has a prescribed concentration.

[0004] Patent Document 1 discloses a technique related to an apparatus for measuring the concentration of such a disinfectant solution by absorptiometry.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-69969 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Since disinfectants such as glutaraldehyde aqueous solution and o-phthalaldehyde aqueous solution have a correlation between temperature, transmittance (or absorbance), and concentration, in order to use the absorbance spectrophotometry method to measure the concentration based on transmittance, it is also necessary to measure the temperature (or it is necessary to measure based on the given temperature conditions).

[0010] Here, as described in Patent Document 1, the concentration measurement of the disinfectant in a concentration measurement device using the absorptiometry method is performed on the disinfectant (sample) contained in an optical cell. However, it is not always easy to accurately measure the temperature of the liquid in such a cell.

[0011] Specifically, it's possible to measure the temperature using a contact-type temperature sensor, such as a thermocouple, in direct contact with the disinfectant solution within the optical cell. However, with a contact-type temperature sensor, if there's a temperature difference between the disinfectant solution and the temperature sensor, the temperature sensor's own heat capacity can affect the temperature. For reasons of workability and minimizing disinfectant waste, the amount of disinfectant within the optical cell is typically several cc, and the effect of the temperature sensor's contact cannot be ignored.

[0012] In order to eliminate such problems, the use of a non-contact temperature sensor has also been considered. However, when a radiation sensor is used as a non-contact sensor, since the radiation temperature from the wall surface of the optical unit is measured, if there is a temperature difference between the optical unit and the disinfectant, the liquid temperature of the disinfectant may not be accurately measured.

[0013] Conventionally, to prevent or reduce these problems, concentration measurement (temperature measurement for this purpose) was performed only after waiting until there was no temperature difference between the disinfectant and the concentration measurement device (optical unit, etc.) (the disinfectant was left at ambient temperature for thermal equilibrium).

[0014] However, such operation is complicated, and there is a demand to perform concentration measurement in a shorter time.

[0015] In view of the above problems, an object of the present invention is to provide a concentration measuring device (and a method for correcting the measured temperature) that measures the concentration of a sample by absorptiometry and can measure the temperature relatively accurately and in a short time.

[0016] Technical solutions to problems

[0017] (Scheme 1)

[0018] A correction method of a measurement temperature of a concentration measuring device, which is a correction method of a measurement temperature in a concentration measuring device that performs a concentration measurement based on a temperature and a transmittance or absorbance of a sample having a correlation among the temperature, the transmittance or absorbance, and a concentration, has the following steps: a step of acquiring first correlation information between a temperature and a transmittance or absorbance of a sample whose concentration is known; a step of measuring values respectively correlated with a temperature, a transmittance or absorbance, and an environmental temperature of the sample whose concentration is known over time by the concentration measuring device provided with a sample temperature sensor, an optical sensor, and an environmental temperature sensor; a step of acquiring second correlation information between first difference information and second difference information, wherein the first difference information is difference information between a measured value of the environmental temperature and a measured value of the temperature of the sample, and the second difference information is difference information between a theoretical temperature and a measured value of the temperature of the sample whose concentration is known, the theoretical temperature being obtained based on the first correlation information with respect to the measured value of the transmittance or absorbance; a step of acquiring difference information between a measured value of the temperature of the sample obtained by the sample temperature sensor and a measured value of the environmental temperature obtained by the environmental temperature sensor in a temperature measurement of the sample in a concentration measurement of a sample whose concentration is unknown, and acquiring correction temperature information based on the second correlation information with respect to the difference information; and a step of correcting the measured value of the temperature of the sample according to the correction temperature information.

[0019] (Scheme 2)

[0020] The correction method of a measurement temperature of a concentration measuring device according to Scheme 1, wherein in the acquisition of the second correlation information, positive and negative second correlation information is respectively acquired according to the positive or negative of the difference between the measured value of the environmental temperature and the measured value of the temperature of the sample whose concentration is known, and the correction temperature information is acquired based on either the positive or negative second correlation information corresponding to the positive or negative of the difference between the measured value of the environmental temperature and the measured value of the temperature of the sample in the measurement of the sample whose concentration is unknown.

[0021] (Scheme 3)

[0022] The correction method of a measurement temperature of a concentration measuring device according to Scheme 1 or 2, wherein in a case where the absolute value of the difference between the measured value of the environmental temperature and the measured value of the temperature of the sample in the concentration measurement of the sample whose concentration is unknown is greater than the absolute value of the maximum value of the difference between the measured value of the environmental temperature and the measured value of the temperature of the sample in the measurement of the sample whose concentration is known, it is set as an error.

[0023] (Scheme 4)

[0024] A concentration measuring device is provided for measuring the concentration of a sample having a correlation among temperature, transmittance or absorbance, and concentration, based on the measurement of temperature and transmittance or absorbance, and comprises: a sample temperature sensor for measuring the temperature of the sample; an optical sensor for measuring the transmittance or absorbance of the sample; an ambient temperature sensor for measuring the ambient temperature; and a storage unit for storing second correlation information between first difference information and second difference information, wherein the first difference information is difference information between a measured value of the ambient temperature obtained by the concentration measuring device and a measured value of the temperature of a calibration sample, and the second difference information is difference information between the measured value of the ambient temperature obtained by the concentration measuring device and the measured value of the temperature of the calibration sample. The value information is difference information between a theoretical temperature and a measured value of the temperature of the calibration sample, wherein the theoretical temperature is obtained based on first correlation information between the temperature of the calibration sample and the transmittance or absorbance relative to the measured value of the transmittance or absorbance of the calibration sample obtained by the concentration measuring device; and a temperature correction unit, which obtains difference information between the measured value of the temperature of the sample obtained by the sample temperature sensor and the measured value of the ambient temperature obtained by the ambient temperature sensor, and corrects the measured value obtained by the sample temperature sensor according to the correction temperature information obtained based on the second correlation information relative to the difference information.

[0025] (Scheme 5)

[0026] According to the concentration measuring device described in Scheme 4, the second correlation information includes positive second correlation information and negative second correlation information corresponding to the positive or negative difference between the measured value of the ambient temperature and the measured value of the sample temperature when the concentration of the calibration sample is measured, and the correction temperature information is obtained based on either the positive second correlation information or the negative second correlation information corresponding to the positive or negative difference between the measured value of the ambient temperature obtained by the ambient temperature sensor and the measured value of the sample temperature obtained by the sample temperature sensor.

[0027] (Scheme 6)

[0028] The concentration measuring device according to claim 4 or 5 is configured to perform error processing when the absolute value of the difference between the ambient temperature measured by the ambient temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a given threshold.

[0029] (Scheme 7)

[0030] A concentration measuring device according to Scheme 4 or 5, wherein, when the absolute value of the difference between the measured value of the ambient temperature obtained by the ambient temperature sensor and the measured value of the temperature of the sample obtained by the sample temperature sensor exceeds a given threshold, processing is performed to wait until the absolute value becomes below the threshold.

[0031] Effects of the Invention

[0032] According to the present invention, it is possible to provide a concentration measuring device (and a method for correcting a measured temperature) that measures the concentration of a sample by absorptiometry and can measure the temperature relatively accurately and in a short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a block diagram schematically showing the configuration of a concentration measuring device according to an embodiment of the present invention.

[0034] Figure 2 This is a flowchart schematically showing a concentration measurement method (mainly a measurement temperature correction method) according to an embodiment of the present invention.

[0035] Figure 3 This is a graph showing an example of the correlation between temperature and transmittance (first correlation information) produced based on a disinfectant having a known concentration.

[0036] Figure 4 The concentration measuring device is used to measure the temperature of the disinfectant with known concentration and the ambient temperature over time, and the difference between the two is T sub1 An example of diagramming.

[0037] Figure 5 This is an example of measuring the transmittance of a disinfectant with a known concentration over time using a concentration measuring device, converting the transmittance into a theoretical temperature based on the first correlation information, and then graphing it.

[0038] Figure 6 The difference between the temperature of the disinfectant with known concentration and the theoretical temperature is T sub2 An example of diagramming.

[0039] Figure 7 It means T sub1 With T sub2 A graph showing an example of the correlation (second correlation information).

[0040] Figure 8 It is further Figure 7 A graph on which the approximate formula (second correlation information) of the graph is plotted.

[0041] Figure 9 This is a graph showing the results of a verification experiment of the concentration measuring device according to the embodiment.

[0042] Figure 10 This is a flowchart showing another example of a part of the processing operation of the concentration measurement method (mainly, the measurement temperature correction method) according to the embodiment. DETAILED DESCRIPTION

[0043] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the following embodiment is one form of embodying the present invention and does not limit the scope of the present invention.

[0044] Figure 1 This is a block diagram schematically showing the configuration of a concentration measuring device according to an embodiment of the present invention.

[0045] The concentration measuring device 1 of this embodiment is a device for measuring the concentration of a disinfectant based on temperature and transmittance or absorbance. The disinfectant is, for example, an aqueous glutaraldehyde solution or an aqueous o-phthalaldehyde solution, which has a correlation between temperature, transmittance or absorbance, and concentration. The device comprises:

[0046] an optical unit OC, which contains a disinfectant solution;

[0047] The radiation temperature sensor 13 functions as both a sample temperature sensor for measuring the temperature of the disinfectant solution and an ambient temperature sensor for measuring the ambient temperature;

[0048] The light emitting unit 141 and the light receiving unit 142 are optical sensors for measuring the transmittance or absorbance of the disinfectant;

[0049] a storage unit 12 that permanently or temporarily stores various data, programs, etc. required for the operation of the device;

[0050] The input unit 15 includes an input mechanism such as an operation button and serves as a user interface;

[0051] an output unit 16 including output means such as a screen and an indicator, serving as a user interface; and

[0052] The control / calculation unit 11 controls each unit of the device and performs various calculation processes, and also functions as a temperature correction unit as described below.

[0053] It should be noted that regarding the above description of "transmittance or absorbance", absorbance is the logarithm of the reciprocal of transmittance, and the difference between transmittance and absorbance does not bring about conceptual differences in the application of the present invention (for example, when treating it as absorbance, it is sufficient to perform conversion based on the above relationship, etc.), so it is simply referred to as "transmittance" below.

[0054] The optical cell OC is a container formed of a member that transmits light emitted from the light emitting unit 141 and contains several cc of disinfectant.

[0055] The optical unit OC is detachable from the concentration measurement device 1 and is basically a single-use (disposable) member.

[0056] The radiation temperature sensor 13 is disposed at a position facing the range where the sterilizing liquid enters the optical unit OC installed in the concentration measuring apparatus 1, and measures the temperature of the sample (sterilizing liquid) in a non-contact manner. The radiation temperature sensor is used to measure the liquid temperature of the sterilizing liquid, and performs temperature measurement based on infrared rays emitted from the surface of the optical unit OC, and thus actually measures the surface temperature of the wall surface of the optical unit OC. Therefore, for example, if there is a temperature difference between the optical unit OC and the sterilizing liquid due to a difference in the environmental temperature of the storage place of the concentration measuring apparatus 1, the optical unit OC, and the installation place of the endoscope cleaning apparatus where the sterilizing liquid enters, and the like, a case where the actual liquid temperature of the sterilizing liquid cannot be correctly measured occurs. In contrast, according to the concentration measuring apparatus 1, the concentration measuring method (mainly, the correction method of measuring the temperature) of the present embodiment, as described below, by correcting the measured value of the radiation temperature sensor 13, the liquid temperature of the sterilizing liquid can be more accurately measured.

[0057] Note that, in the present embodiment, the case where the reference temperature sensor provided in the radiation temperature sensor 13 is used as the environmental temperature sensor is exemplified, and thus the radiation temperature sensor 13 has both the functions of the sample temperature sensor and the environmental temperature sensor. Hereinafter, for convenience, it is referred to as "sample temperature sensor 131" as the sample temperature sensor, and as "environmental temperature sensor 132" as the environmental temperature sensor.

[0058] The radiation temperature sensor 13 is connected to the control / computation unit 11, and the reading of the sensor value and the like is controlled by the control / computation unit 11.

[0059] The light emitting portion 141 and the light receiving portion 142 of the optical sensor used to measure the transmittance of the sterilizing liquid are respectively configured so that the optical axis of the light emitting portion 141 passes through the sterilizing liquid inside the optical unit OC, and the light receiving portion 142 can receive the light that has passed through the sterilizing liquid. Here, the case where the light emitting portion 141 is disposed so as to oppose one side of the optical unit OC, and the light receiving portion 142 is disposed so as to oppose the opposite side is exemplified, but as long as the light emitting portion 141 and the light receiving portion 142 are configured so that the light that has passed through the sterilizing liquid can be received, they can be arbitrarily disposed.

[0060] The light emitting portion 141 is connected to the control / computation unit 11 via a drive circuit 1411 that drives the light emission, and the timing of the light emission and the like is controlled by the control / computation unit 11.

[0061] The light receiving portion 142 is also connected to the control / computation unit 11, and the control of the reading of the sensor value, the calculation processing of the transmittance based on the sensor value, and the like are performed by the control / computation unit 11.

[0062] The input unit 15 and the output unit 16 as user interfaces can use any input interface such as buttons, a touch panel, or a voice input unit, and any output interface such as a visual display device such as a pointer or a display screen, or an auditory output unit such as a speaker.

[0063] It should be noted that the input / output unit is not limited to an interface for a user, and may be any input / output unit for inputting and outputting information with other devices.

[0064] The storage unit 12 may be any storage device that can store various data, programs, and the like required for the operation of the device.

[0065] The storage unit 12 stores programs for executing the processing described below and data required for the temperature calibration process. One example of this data is "second correlation information between first difference information (the difference between the ambient temperature measured by the concentration measuring device 1 and the temperature of the calibration sample (a disinfectant with a known concentration)) and second difference information (the difference between a theoretical temperature obtained based on the first correlation information between the temperature and transmittance of the calibration sample, relative to the transmittance measured by the concentration measuring device 1) and the temperature of the calibration sample." This information is described in detail below.

[0066] The control / calculation unit 11 controls each unit of the device and performs various calculations, and is configured using, for example, an arbitrary semiconductor device such as a microcomputer equipped with a CPU (Central Processing Unit) that performs calculations.

[0067] The control / calculation unit 11 also functions as a temperature correction unit for performing the process described below of "obtaining difference information between the temperature measurement value of the disinfectant obtained by the sample temperature sensor 131 and the ambient temperature measurement value obtained by the ambient temperature sensor 132, obtaining corrected temperature information based on the second correlation information with respect to the difference information, and correcting the measurement value obtained by the sample temperature sensor 131 based on the corrected temperature information."

[0068] Furthermore, the device also functions as a concentration calculation unit that calculates the concentration of the disinfectant based on the corrected temperature information and transmittance information of the disinfectant.

[0069] It should be noted that although omitted in the figure, the control / calculation unit 11 can of course be connected to each unit via an A / D conversion circuit, various filter circuits, etc. as needed (a circuit is appropriately set up to form a signal that is suitable as an input and output to the control / calculation unit 11).

[0070] Here, the temperature correction unit, concentration calculation unit, etc. are illustrated as being installed in a general-purpose device in a software manner (composed of a program operating on the control / calculation unit 11), but part or all of each may also be composed of hardware (for example, by a dedicated IC, etc.).

[0071] Next, refer to Figure 2 The concentration measurement method (mainly, the measurement temperature correction method) of this embodiment will be described.

[0072] Figure 2 This flowchart outlines the concentration measurement method (primarily the measurement temperature correction method) of this embodiment. Flowcharts 1 through 5 describe the calibration process (setting parameters for temperature correction) of the radiation temperature sensor 13, performed in each concentration measurement device 1 within the device's manufacturing facility. Flowcharts 6 through 8 describe the concentration measurement process (and the associated measurement temperature correction) performed by the concentration measurement device 1.

[0073] In process 1, first correlation information between temperature and transmittance is obtained based on a disinfectant (calibration sample) having a known concentration.

[0074] Specifically, multiple disinfectants with different concentrations, whose concentrations have been measured by HPLC (high performance liquid chromatography), are prepared. For each concentration of disinfectant, the transmittance is measured under constant temperature conditions such as 10°C, 15°C, 20°C, 25°C, 30°C, and 35°C, for example, by holding the disinfectants in a constant temperature bath for a certain period of time.

[0075] Figure 3 An example of a graph showing the correlation between temperature and transmittance of the disinfectant (calibration sample) obtained in this manner is shown in Figure 2. It should be noted that the concentration range of the disinfectant to be measured can be determined based on the actual concentration during use. Here, given that the concentration of the disinfectant (product) being tested is 0.55% when new and has a usage limit of 0.3%, measurements were performed within the range of 0.55-0.20%.

[0076] Next, find Figure 3 Approximate formula of the graph (function of concentration N, temperature T, and transmittance k).

[0077] The concentration N is calculated by the following formula 1 using the temperature T and the transmittance k.

[0078] (Formula 1)

[0079] N=iT 2 k 2 +hTk 2 +gk 2 +fT 2 k+eTk+dk+cT 2 +bT+a

[0080] It should be noted that a to i are coefficients.

[0081] In the following formula 2 obtained by transforming formula 1, if A=iT 2 +hT+g、B=fT 2 +eT+d、C=cT 2 +bT+a, it becomes a quadratic function of k (Formula 3).

[0082] (Equation 2)

[0083] N=(iT 2 +hT+g)k 2 +(fT 2 +eT+d)k+(cT 2 +bT+a)

[0084] (Equation 3)

[0085] N=Ak 2 +Bk+C

[0086] In Formula 3, A, B, and C are calculated by the least squares method, and coefficients a to i are calculated by the least squares method based on the obtained A to C (quadratic functions of T).

[0087] Thus, we get Figure 3 The coefficients of Equation 1 are approximated by the graph.

[0088] It should be explained that Figure 3 Any of the information on the graphical state of (or information used therefor) and the information as an approximate expression obtained based thereon corresponds to the “first correlation information”.

[0089] The calculation process of the “first correlation information” is performed on an information processing device (different from the concentration measurement device 1 ) such as a PC having an application for calculating the above-mentioned approximate formula, but may be configured to be executable on the concentration measurement device 1 .

[0090] In flow 2 , using the concentration measuring device 1 to be calibrated, values ​​related to the temperature, transmittance, and ambient temperature of a calibration sample (a disinfectant with a known concentration) are measured over time.

[0091] More specifically, a concentration measurement device 1 (optical cell OC) temperature-controlled at an ambient (surrounding) temperature (e.g., 15°C) and a calibration sample temperature-controlled at a different temperature (e.g., 30°C) are prepared. The concentration measurement device 1 is used to measure the temperature, transmittance, and ambient temperature of the calibration sample over time. Data is obtained as the optical cell OC and the calibration sample placed therein, each at a different temperature, gradually reach thermal equilibrium. This temporal measurement is preferably performed until a state can be considered thermally equilibrium (a state in which the temperature difference between the ambient temperature and the liquid temperature has disappeared).

[0092] Then, the first difference information T is calculated, which is the difference between the measured value of the ambient temperature at each time and the measured value of the temperature of the calibration sample. sub1 (This calculation process uses an information processing device such as a PC as an external device in the same manner as described above, but may also be performed by the concentration measuring device 1).

[0093] As described above, the processing of process 2 is performed under conditions where the ambient temperature (temperature of the concentration measuring device 1 (optical unit OC)) and the temperature of the calibration sample are different, and the difference in temperature is reversed (for example, in contrast to the above example, the ambient temperature is 30°C and the temperature of the calibration sample is 15°C). It should be noted that the ambient temperature and the temperature of the calibration sample can be set to a value close to the maximum value of the temperature difference that can be assumed in the actual use environment of the concentration measuring device 1. Here, it is assumed that 1. The ambient temperature is 15°C and the calibration sample temperature is 30°C ( Figure 4 (a)), 2. Ambient temperature 30°C, calibration sample temperature 15°C ( Figure 4 As an example, consider the conditions of (b) in step 1. It should be noted that slight differences in disinfectant concentration do not significantly affect thermal equilibrium behavior. Therefore, the concentration of the calibration sample used to obtain data on the gradual thermal equilibrium process can be set to any concentration (for example, any concentration within the concentration range used in step 1). However, a disinfectant with a concentration of 0.3% as the working limit is used here.

[0094] Figure 4 An example of the data obtained in process 2 is shown in FIG. object is the temperature of the calibration sample obtained by the sample temperature sensor 131, T PTAT is the ambient temperature obtained by the ambient temperature sensor 132, T sub1 is the difference between the two. Figure 4 (a) indicates that the liquid temperature is higher than the ambient temperature. Figure 4 (b) indicates a case where the liquid temperature is lower than the ambient temperature.

[0095] It should be noted that, here, T sub1 It is from T PTAT Subtract Tobject As an example, the value obtained can be set from T object Subtract T PTAT The obtained value (in the process described below, the sign may be reversed as needed; the difference in sign does not lead to a difference in concept) is obtained.

[0096] In process 3, a process of calculating the theoretical temperature based on the first correlation information is performed on the transmittance measurement values ​​of the calibration sample measured over time using the concentration measurement device 1 in process 2.

[0097] That is, in the formula 1 as the first correlation information, the temperature T (theoretical temperature T ref ) processing.

[0098] Figure 5 The calculated theoretical temperature T is shown in ref A diagrammed example. Figure 5 (a) indicates the case where the liquid temperature is higher than the ambient temperature (when the liquid temperature gradually decreases due to thermal equilibrium). Figure 5 (b) shows the case where the liquid temperature is lower than the ambient temperature (the case where the liquid temperature gradually rises due to thermal equilibrium).

[0099] The processing in flow 3 is also performed on an information processing device such as a PC (a device different from the concentration measurement device 1 ), but may also be configured to be executed on the concentration measurement device 1 .

[0100] In process 4, the theoretical temperature T calculated in process 3 is calculated. ref The temperature T of the calibration sample obtained by the sample temperature sensor 131 object The difference is the second difference information T sub2 , obtain the second difference information T sub2 and the first difference information T obtained in process 2 sub1 The second correlation information between them.

[0101] Figure 6 is the theoretical temperature T calculated in process 3 ref , Temperature of the calibration sample T object , and the second difference information T as their difference sub2 The diagram after graphing. Figure 6 (a) indicates that the liquid temperature is higher than the ambient temperature. Figure 6 (b) indicates a case where the liquid temperature is lower than the ambient temperature.

[0102] Figure 7 The second difference information T sub2Set as Y axis, the first difference information T sub1 Set the X-axis of the graph (second correlation information). Figure 7 (a) indicates that the liquid temperature is higher than the ambient temperature (negative second correlation information), Figure 7 (b) indicates that the liquid temperature is lower than the ambient temperature (positive second correlation information). sub2 Set as Y axis, the first difference information T sub1 Assume that the X axis is used as an example, but the second difference information T sub2 Set as X axis, the first difference information T sub1 Set as the Y-axis (there is no conceptual difference between the two).

[0103] In process 5, find Figure 7 Graph (second difference information T sub2 and the first difference information T sub1 function of ).

[0104] In the present embodiment, exponential function approximation (calculation of coefficients a1, b1, and c1) is performed based on Formula (4).

[0105] (Formula 4)

[0106] T sub2 =a1·e （b1·Tsub1） +c1

[0107] Figure 8 The obtained approximate formula is shown in a graph. Figure 8 (a) indicates that the liquid temperature is higher than the ambient temperature (negative second correlation information), Figure 8 (b) indicates a case where the liquid temperature is lower than the ambient temperature (positive second correlation information). That is, coefficients a1, b1, and c1 corresponding to negative second correlation information and coefficients a1, b1, and c1 corresponding to positive second correlation information are obtained.

[0108] It should be explained that Figure 8 Any of the information on the graphical state of (or information used therefor) and the information as an approximate expression obtained based thereon corresponds to the “second correlation information”.

[0109] The processing 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 different from the concentration measurement device 1 ), but may also be configured to be executed on the concentration measurement device 1 .

[0110] The above processes 1 to 5 are performed on each concentration measuring device 1 in the manufacturing plant, and the parameters of the coefficients a1, b1, c1 (the coefficients a1, b1, c1 corresponding to the negative second correlation information, and the coefficients a1, b1, c1 corresponding to the positive second correlation information) constituting the "second correlation information" corresponding to each concentration measuring device 1 are set for each concentration measuring device 1 (stored in the storage unit 12), thereby performing calibration processing of the radiation temperature sensor 13 (setting of parameters for temperature correction).

[0111] The concentration of the disinfectant is measured using the concentration measuring device 1 through the processes of Flows 6 to 8. The concentration calculation process (Flow 8) itself can be performed using conventional methods as is, so its description is omitted here. The following will focus on the calibration of the disinfectant's measurement temperature, which is required for concentration calculation.

[0112] The concentration of a disinfectant (a sample of unknown concentration) is measured using the concentration measuring device 1. With the optical unit OC placed in the device and the disinfectant placed therein, the concentration is measured based on measurement of the disinfectant's temperature by the sample temperature sensor 131, measurement of the ambient temperature by the ambient temperature sensor 132, and measurement of the transmittance of the disinfectant by the light emitting unit 141 and the light receiving unit 142.

[0113] In flow 6 , the positive or negative value of the value obtained by subtracting the temperature measurement value of the disinfectant obtained by the sample temperature sensor 131 from the ambient temperature measurement value obtained by the ambient temperature sensor 132 is determined.

[0114] If the result of this determination is negative, the processes of flows 7-1 and 8-1 are executed, and if it is positive, the processes of flows 7-2 and 8-2 are executed. Note that, here, 0 is used as a negative process, but 0 may also be used as a positive process.

[0115] In flow 7-1, the control / calculation unit 11 performs the following processing: a value (T sub1 ) into the approximate formula (4) (with Figure 8 (a) corresponds to the negative second correlation information), calculate the temperature difference information (T sub2 ).

[0116] Then, the control / calculation unit 11 performs the following processing: by using (adding) the temperature difference information (T sub2 ), correct the temperature measurement value of the disinfectant obtained by the sample temperature sensor 131.

[0117] In process 8-1, the control / calculation unit 11 performs processing for calculating the concentration of the disinfectant using the temperature information of the disinfectant corrected in process 7-1 and the measured value of the transmittance of the disinfectant.

[0118] It should be noted that when the judgment result of process 6 is positive, the processing of processes 7-2 and 8-2 is replaced by "with Figure 8 (a) corresponds to the negative second correlation information" and uses "with Figure 8 Except for the point that "positive second correlation information corresponding to (b)" is obtained, the processing is the same as that of processes 7-1 and 8-1, and therefore the description is omitted.

[0119] Figure 9 3 shows the concentration measurement results of a disinfectant having a concentration of 0.3% using the concentration measuring device 1 (the results of a verification experiment).

[0120] To illustrate the effect of temperature correction achieved by the concentration measuring device 1 , values ​​calculated at the temperature before correction (ie, using the measured value of the sample temperature sensor 131 as it is) and values ​​calculated at the temperature after correction are shown. Figure 9 (a) indicates a case where the liquid temperature is higher than the ambient temperature (the liquid temperature at the start of the measurement is set to approximately 25°C, and the ambient temperature is set to approximately 15°C). Figure 9 (b) shows a case where the liquid temperature is lower than the ambient temperature (the liquid temperature at the start of measurement is set to about 20° C., and the ambient temperature is set to about 30° C.).

[0121] In the graph, the dotted line shows a range of ±0.01 with respect to the concentration of 0.3% as the standard.

[0122] As shown in the figure, the concentration based on the pre-calibration temperature falls outside the ±0.01 range relative to the disinfectant's original concentration of 0.3% for less than 20 seconds from the start of measurement when the liquid temperature is set at approximately 25°C and the ambient temperature is set at approximately 15°C, and for approximately 45 seconds from the start of measurement when the liquid temperature is set at approximately 20°C and the ambient temperature is set at approximately 30°C. This means that conventionally, measurements have required waiting for a minimum amount of time (since it was impossible to accurately determine the optimal waiting time, a waiting time of at least 60 seconds was required for safety reasons).

[0123] In contrast, when the temperature correction of the present embodiment is used, a concentration measurement value within the standard can be obtained about 5 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, or 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, thereby enabling concentration measurement to be performed in a short time.

[0124] It should be noted that immediately after the disinfectant is injected into the optical unit, the measured value may become unstable due to the movement of the liquid caused by the injection, the generation of bubbles, etc. (considered to be Figure 9 The data deviation immediately after the start of (b) is also greatly affected by this. Therefore, a predetermined waiting time (eg, about 10 to 15 seconds) may be set until the liquid in the optical cell stabilizes.

[0125] As described above, the concentration measuring device 1 and the temperature calibration method of this embodiment enable accurate measurement (calibration) of the disinfectant temperature even when there is a temperature difference between the ambient temperature and the disinfectant liquid temperature. This shortens or eliminates the waiting time, which is typically required until the ambient temperature and the disinfectant liquid temperature become equal, enabling concentration measurement to be performed in a shorter time.

[0126] While accurately measuring the disinfectant's temperature can be challenging when obtaining the calibration curve used for this correction, this embodiment solves this problem by leveraging the correlation between disinfectant temperature and transmittance to determine the liquid temperature (theoretical temperature) based on the transmittance. This allows for a correlation (i.e., a calibration curve for correction) between the apparent disinfectant temperature (cell wall temperature) measured by the sensor and the estimated actual disinfectant temperature (theoretical temperature).

[0127] In this embodiment, positive second correlation information and negative second correlation information are acquired corresponding to the sign of the difference between the measured value of the ambient temperature and the measured value of the sample temperature when measuring the concentration of the calibration sample.

[0128] This is because different trends were observed in the direction of decreasing and increasing liquid temperature, and therefore these trends were treated separately (to further improve accuracy). This trend is believed to be influenced by, for example, the heat generated by the concentration measuring device, which is an electronic device. Specifically, the heat generated by the light-emitting unit and other electronic components during operation tends to increase the liquid temperature, resulting in different trends (asymmetry) in the direction of decreasing and increasing liquid temperature.

[0129] Therefore, even in a device having a structure in which the influence of heat or the like of electronic components can be ignored, correction can be performed using only one piece of “second correlation information” without distinguishing between positive second correlation information and negative second correlation information.

[0130] Alternatively, by introducing a correction value that evaluates the "offset due to the influence of heat of the electronic component," correction may be performed using only one piece of "second correlation information" (the offset amount may be further corrected using the correction value).

[0131] When there is no temperature difference between the ambient temperature and the liquid temperature of the disinfectant (i.e., T sub1 is close to 0), the correction process described above is not necessary, so in the T sub1 When the value is close to 0 (less than or equal to a predetermined value), the concentration may be calculated based on the measurement value of the sample temperature sensor 131 without performing the temperature correction process of flow 7 .

[0132] In addition, in a case where the difference (absolute value) between the measured value of the ambient temperature and the measured value of the temperature of the sample 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 value of the ambient temperature and the measured value of the temperature of the sample when measuring the calibration sample (a sample with a known concentration), an error process such as outputting an error message to the output unit 16 may be performed.

[0133] Data outside the range used for correction is treated as an error.

[0134] It should be noted that, instead of taking error action, the process may be performed by waiting until the temperature difference between the ambient temperature and the liquid temperature of the disinfectant becomes less than the maximum value of the difference between the measured value of the ambient temperature and the measured value of the sample temperature when measuring the calibration sample due to thermal equilibrium.

[0135] Figure 10 An example of this processing is shown in FIG.

[0136] Figure 10 The treatment is to replace Figure 2 The processing of the part of process 6. As a premise of this processing, the T obtained by the processing of process 2 sub1 The absolute value of the maximum value (both positive and negative) of is set in the concentration measurement device 1 (storage unit 12) as thresholds 1 and 2. For example, in the process of flow 2, when the ambient temperature is 16°C and the calibration sample temperature is 29°C, 13°C is set as threshold 1, and when the ambient temperature is 31°C and the calibration sample temperature is 15°C, 16°C is set as threshold 2.

[0137] In step 901, it is determined whether a value (T sub1 ) obtained by subtracting the measured value of the temperature of the sterilizing solution obtained by the sample temperature sensor 131 from the measured value of the ambient temperature obtained by the ambient temperature sensor 132 is positive or negative.

[0138] The processing of steps 902 and 903 is performed in the case where the result of the determination is negative, and the processing of steps 904 and 905 is performed in the case where the result of the determination is positive. Note that the processing in which 0 is set to be negative, but the processing in which 0 is set to be positive can also be performed. Further, as described above, in the case of 0, the temperature correction processing can also be skipped.

[0139] In step 902, it is determined whether the absolute value of T sub1 exceeds a threshold value 1, and in the case where it exceeds, a display such as "on standby until the liquid temperature becomes a measurable condition (or only'measuring')" is performed in the output section 16 (step 903). Until the absolute value of T sub1 becomes equal to or less than the threshold value 1, the loop processing of steps 902 to 903 is performed.

[0140] In the determination in step 902, in the case where the absolute value of T sub1 is equal to or less than the threshold value 1, the flow 7-1 of Figure 2 is shifted to, and the correction processing is performed.

[0141] Note that the processing of steps 904 and 905 in the case where the result of the determination in step 901 is positive is the same as the processing of steps 902 and 903 except for the point that the threshold value 2 is used instead of the threshold value 1, and thus the description is omitted.

[0142] Note that in the embodiment, as the measurement object of the concentration, the sterilizing solution such as a glutaraldehyde aqueous solution, an o-phthaldehyde aqueous solution, or the like is exemplified, but the present application is not limited thereto, and the concept of the present application can be applied to any sample having a correlation between the temperature, the transmittance or absorbance, and the concentration.

[0143] In the embodiment, as the temperature sensor, the non-contact type temperature sensor, that is, the radiation temperature sensor is exemplified, but the present application is not limited thereto. For example, in a structure in which the temperature of the optical unit is measured by any temperature sensor such as a contact type temperature sensor, the concept of the present application can be applied.

[0144] Further, as the ambient temperature sensor that measures the ambient temperature, the reference temperature sensor provided in the radiation temperature sensor is exemplified, but the present application is not limited thereto, and any temperature sensor that can measure the ambient temperature can be provided separately.

[0145] Symbol explanation

[0146] 1: concentration measurement device

[0147] 11: control / arithmetic unit (temperature correction unit)

[0148] 12: storage unit

[0149] 13: radiation temperature sensor (sample temperature sensor, ambient temperature sensor)

[0150] 141: light emitting unit (optical sensor)

[0151] 142: light receiving unit (optical sensor)

Claims

1. A method for calibrating the measurement temperature of a concentration measuring device, comprising the steps of: a step of obtaining first correlation information between temperature and transmittance or absorbance based on a sample with known concentration; The step of measuring, over time, values ​​related to the temperature, transmittance or absorbance of a sample of known concentration, and the ambient temperature using a concentration measuring device equipped with a sample temperature sensor, an optical sensor, and an ambient temperature sensor; The step of obtaining second correlation information between the first difference information and the second difference information, wherein: The first difference information is difference information between a measured value of the ambient temperature and a measured value of the sample temperature, and the second difference information is difference information between a theoretical temperature and a measured value of the temperature of the sample with a known concentration, the theoretical temperature being obtained based on the first correlation information with respect to the measured value of the transmittance or absorbance; In measuring the temperature of a sample in measuring the concentration of a sample with an unknown concentration, obtaining difference information between a temperature measurement value of the sample obtained by the sample temperature sensor and a temperature measurement value of the ambient temperature obtained by the ambient temperature sensor, and obtaining corrected temperature information based on the second correlation information with respect to the difference information; and a step of correcting the measured value of the temperature of the sample based on the corrected temperature information.

2. The method for calibrating the measurement temperature of a concentration measuring device according to claim 1, wherein: In acquiring the second correlation information, positive second correlation information and negative second correlation information are acquired according to the sign of the difference between the measured value of the ambient temperature when the concentration of the sample with known concentration is measured and the measured value of the temperature of the sample, respectively. The corrected temperature information is acquired based on either the positive second correlation information or the negative second correlation information, corresponding to the sign of the difference between the measured value of the ambient temperature and the measured value of the sample temperature when measuring the sample with unknown concentration.

3. The method for calibrating the measurement temperature of a concentration measuring device according to claim 1 or 2, wherein: If the absolute value of the difference between the ambient temperature measured value and the sample temperature measured when measuring the concentration of the sample with unknown concentration is greater than the maximum absolute value of the difference between the ambient temperature measured value and the sample temperature measured when measuring the sample with known concentration, it is considered an error.

4. A concentration measuring device for measuring the concentration of a sample having a correlation between temperature and transmittance or absorbance and concentration by measuring the temperature and transmittance or absorbance, comprising: a sample temperature sensor, which is used to measure the temperature of the sample; Optical sensors for measuring the transmittance or absorbance of a sample; An ambient temperature sensor, which is used to measure the ambient temperature; a storage unit storing second correlation information between first difference information and second difference information, the first difference information being difference information between a measured value of an ambient temperature obtained by the concentration measuring device and a measured value of a temperature of a calibration sample having a known concentration, and the second difference information being difference information between a theoretical temperature and a measured value of the temperature of the calibration sample having a known concentration, the theoretical temperature being obtained based on the first correlation information between the temperature and the transmittance or absorbance of the calibration sample having a known concentration, with respect to the measured value of the transmittance or absorbance of the calibration sample having a known concentration obtained by the concentration measuring device; and A temperature correction unit obtains difference information between a temperature measurement value of the sample obtained by the sample temperature sensor and a temperature measurement value of the ambient temperature obtained by the ambient temperature sensor, and corrects the temperature measurement value obtained by the sample temperature sensor based on correction temperature information obtained based on the second correlation information relative to the difference information.

5. The concentration measuring device according to claim 4, wherein The second correlation information includes positive second correlation information and negative second correlation information corresponding to the sign of the difference between the measured value of the ambient temperature and the measured value of the sample temperature when the concentration of the calibration sample having a known concentration is measured. The corrected 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 ambient temperature measured by the ambient temperature sensor and the sample temperature measured by the sample temperature sensor is positive or negative.

6. The concentration measuring device according to claim 4 or 5, wherein: When the absolute value of the difference between the ambient temperature measured by the ambient temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold, error processing is performed.

7. The concentration measuring device according to claim 4 or 5, wherein When the absolute value of the difference between the ambient temperature measured by the ambient temperature sensor and the sample temperature measured by the sample temperature sensor exceeds a predetermined threshold, processing is performed to wait until the absolute value becomes less than the threshold.

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