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

Abstract

Provided is a concentration measurement device that measures the concentration of a sample by absorbance spectrophotometry and that can perform temperature measurement in a shorter time than in the prior art. A concentration measurement device (1) is provided with: a sample temperature sensor (13) for measuring the temperature of a sample; optical sensors (141, 142) for measuring the transmittance of the sample; an ambient temperature sensor (13) that measures the ambient temperature; and a storage unit (12) that stores second correlation information between first difference information between a measured value of the ambient temperature obtained by the concentration measurement device (1) and a measured value of the temperature of the calibration sample, and second difference information between the measured value of the ambient temperature and the measured value of the temperature of the calibration sample. The second difference information is difference information between a theoretical temperature and a measured value of the temperature of the correction sample, the theoretical temperature being obtained on the basis of first correlation information between the temperature of the correction sample and the transmittance with respect to a measured value of the transmittance of the correction sample obtained by the concentration measurement device (1); and a temperature correction unit (11) that acquires difference information between the measured value of the temperature of the sample to be measured and the measured value of the ambient temperature, and corrects the measured value of the temperature of the sample to be measured on the basis of corrected temperature information obtained on the basis of the second correlation information with respect to the difference information.

Description

Technical Field

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

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

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

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

[0005] Prior art literature Patent Literature Patent Document 1: Japanese Patent Application Publication No. 2005-69969 Summary of the invention Problems to be solved by the invention 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 to measure the concentration based on the transmittance, it is also necessary to measure the temperature (or it is necessary to measure based on a given temperature condition).

[0006] Here, the concentration measurement of the disinfectant in the concentration measurement device using the absorptiometry is performed on the disinfectant (sample) contained in the optical cell as described in Patent Document 1. However, it is not always easy to accurately measure the temperature of the liquid in such a cell.

[0007] Specifically, it is considered that a contact-type temperature sensor such as a thermocouple is brought into direct contact with the disinfectant in the optical unit to measure the temperature. However, in the case of a contact-type temperature sensor, if there is a temperature difference between the disinfectant and the temperature sensor, there is a problem that the temperature sensor itself is affected by its own heat capacity. From the perspective of workability and not wasting disinfectant, the amount of disinfectant in the optical unit is about several cc, and the influence caused by the contact of the temperature sensor cannot be ignored.

[0008] In order to eliminate such problems, the use of non-contact temperature sensors is also considered. However, when a radiation sensor is used as a non-contact sensor, since the radiation temperature from the wall 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.

[0009] Conventionally, in order to prevent or reduce these problems, concentration measurement (temperature measurement for this purpose) was performed 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).

[0010] However, such operation is complicated, and there is a demand to perform concentration measurement in a shorter time.

[0011] 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) which measures the concentration of a sample by an absorptiometry method and can measure the temperature relatively accurately and in a short time.

[0012] Technical solutions to solve problems (Scheme 1) A method for correcting the measured temperature of a concentration measuring device, which is a method for correcting the measured temperature in a concentration measuring device for measuring the concentration of a sample having correlation among temperature, transmittance or absorbance, and concentration based on the measurement of temperature and transmittance or absorbance, comprising the following steps: a step of obtaining first correlation information between temperature and transmittance or absorbance based on a sample with known concentration; a step of measuring values ​​respectively related to the temperature, transmittance or absorbance, and ambient temperature of the sample with known concentration over time by a concentration measuring device having a sample temperature sensor, an optical sensor, and an ambient temperature sensor; a step of obtaining second correlation information between first difference information and second difference information, wherein the first difference information is a first correlation information between the first difference information and the second difference information. The value information is the difference information between the measured value of the ambient temperature and the measured value of the temperature of the sample, the second difference information is the difference information between the theoretical temperature and the measured value of the temperature of the sample with known concentration, the theoretical temperature is obtained based on the first correlation information relative to the measured value of the transmittance or absorbance; in the temperature measurement of the sample in the concentration measurement of the sample with unknown concentration, the 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 is obtained, and the corrected temperature information based on the second correlation information relative to the difference information is obtained; and the step of correcting the measured value of the temperature of the sample according to the corrected temperature information.

[0013] (Solution 2) According to the method for correcting the measured temperature of the concentration measuring device described in Scheme 1, in obtaining the second correlation information, positive second correlation information and negative second correlation information are respectively obtained according to the positive or negative value of the difference between the measured value of the ambient temperature when measuring the concentration of the sample with a known concentration and the measured value of the temperature of the sample, 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 value of the difference between the measured value of the ambient temperature when measuring the sample with an unknown concentration and the measured value of the temperature of the sample.

[0014] (Scheme 3) A method for correcting the measured temperature of a concentration measuring device according to Scheme 1 or 2, wherein an error is set when the absolute value of the difference between the measured value of the ambient temperature when measuring the concentration of a sample with an unknown concentration and the measured value of the temperature of the sample is greater than the absolute value of the maximum value of the difference between the measured value of the ambient temperature when measuring the sample with a known concentration and the measured value of the temperature of the sample.

[0015] (Scheme 4) A concentration measuring device is a concentration measuring device that measures the concentration of a sample having 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 the calibration sample, and the second difference information is 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 correction temperature information obtained based on the second correlation information relative to the difference information.

[0016] (Scheme 5) 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 and negative values ​​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 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 and negative values ​​of the 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.

[0017] (Scheme 6) The concentration measuring device according to claim 4 or 5, wherein error processing is performed 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.

[0018] (Scheme 7) 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.

[0019] Effects of the Invention According to the present invention, it is possible to provide a concentration measuring device (and a method for correcting a measured temperature) which measures the concentration of a sample by an absorptiometry method and can measure the temperature relatively accurately and in a short time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a block diagram schematically showing the structure of a concentration measuring device according to an embodiment of the present invention.

[0021] 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.

[0022] 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.

[0023] Figure 4 The concentration measuring device measures the temperature of the disinfectant with known concentration and the ambient temperature over time, and the difference between the two, i.e., T sub1 An example of diagramming.

[0024] Figure 5This is an example in which the transmittance of a disinfectant having a known concentration is measured over time by a concentration measuring device, and the transmittance is converted into a theoretical temperature based on the first correlation information and then graphed.

[0025] Figure 6 It is the difference between the temperature of the disinfectant with known concentration and the theoretical temperature, i.e. T sub2 An example of diagramming.

[0026] Figure 7 It means T sub1 With T sub2 A graph of an example of the correlation (second correlation information).

[0027] Figure 8 It is further Figure 7 A graph on which the approximate formula (second correlation information) of the graph is plotted.

[0028] Fig. 9 This is a graph showing the results of a verification experiment of the concentration measuring device according to the embodiment.

[0029] Fig.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

[0030] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that the following embodiment is one mode for implementing the present invention, and the present invention is not limited to the scope thereof.

[0031] Figure 1 This is a block diagram schematically showing the structure of a concentration measuring device according to an embodiment of the present invention.

[0032] The concentration measuring device 1 of the present embodiment is a concentration measuring device for measuring the concentration of a disinfectant based on the measurement of temperature and transmittance or absorbance. The disinfectant is a glutaraldehyde aqueous solution, an o-phthalaldehyde aqueous solution, or the like, which has a correlation between temperature, transmittance or absorbance, and concentration. The concentration measuring device comprises: an optical unit OC, which contains a disinfectant solution; The radiation temperature sensor 13 functions as both a sample temperature sensor for measuring the temperature of the disinfectant solution and an environment temperature sensor for measuring the environment temperature; The light emitting unit 141 and the light receiving unit 142 are optical sensors for measuring the transmittance or absorbance of the disinfectant; A storage unit 12 that permanently or temporarily stores various data, programs, etc. required for the operation of the device; An input unit 15, which has an input mechanism such as an operation button and serves as a user interface; An output unit 16, which includes output means such as a screen and an indicator, and serves as a user interface; and 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.

[0033] It should be noted that regarding the above-mentioned point recorded as "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 treating it as absorbance, it is sufficient to perform a conversion based on the above-mentioned relationship, etc.), so it is hereinafter referred to as "transmittance".

[0034] The optical cell OC is a container formed of a member that transmits the light emitted by the light emitting unit 141 , and contains several cc of disinfectant.

[0035] The optical cell OC is detachable from the concentration measuring device 1 and is basically a single-use (disposable) member.

[0036] The radiation temperature sensor 13 is provided at a position facing the range of the optical unit OC installed in the concentration measuring device 1 for the disinfectant to enter, and measures the temperature of the sample (disinfectant) in a non-contact manner. The radiation temperature sensor is used to measure the liquid temperature of the disinfectant, and the temperature is measured based on infrared rays emitted from the surface of the optical unit OC, so the surface temperature of the wall surface of the optical unit OC is actually measured. Therefore, for example, if there is a temperature difference between the optical unit OC and the disinfectant due to the difference in ambient temperature between the storage place of the concentration measuring device 1 and the optical unit OC and the installation place of the endoscope cleaning device for the disinfectant to enter, the actual liquid temperature of the disinfectant cannot be correctly measured. In contrast, according to the concentration measuring device 1 and the concentration measuring method (mainly the correction method of the measured temperature) of the present embodiment, as described below, by correcting the measured value of the radiation temperature sensor 13, the liquid temperature of the disinfectant can be measured more accurately.

[0037] It should be noted that in this embodiment, the reference temperature sensor provided by the radiation temperature sensor 13 is used as an example of an environmental temperature sensor, and therefore the radiation temperature sensor 13 has the functions of both a sample temperature sensor and an environmental temperature sensor. Hereinafter, for convenience, the sample temperature sensor is referred to as "sample temperature sensor 131", and the environmental temperature sensor is referred to as "environmental temperature sensor 132".

[0038] The radiation temperature sensor 13 is connected to the control / calculation unit 11 , and the reading of the sensor value and the like are controlled by the control / calculation unit 11 .

[0039] The light emitting unit 141 and the light receiving unit 142, which are optical sensors for measuring the transmittance of the disinfectant, are respectively arranged so that the optical axis of the light emitting unit 141 passes through the disinfectant in the optical unit OC, and the light receiving unit 142 can receive the light that has passed through the disinfectant. Here, the light emitting unit 141 is arranged opposite to one side of the optical unit OC, and the light receiving unit 142 is arranged opposite to the opposite side, but the light emitting unit 141 and the light receiving unit 142 can be arranged in any configuration as long as they are structures that can receive the light that has passed through the disinfectant.

[0040] The light emitting unit 141 is connected to the control / calculation unit 11 via a driving circuit 1411 that drives the light emission, and the timing of light emission and the like are controlled by the control / calculation unit 11 .

[0041] The light receiving unit 142 is also connected to the control / calculation unit 11 , and the control / calculation unit 11 performs control of reading of sensor values, calculation processing of transmittance based on the sensor values, and the like.

[0042] The input unit 15 and the output unit 16 as user interfaces can use any input interface such as buttons, touch panels, or voice input units, and any output interface such as visual display devices such as indicators and display screens, and auditory output units such as speakers.

[0043] 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.

[0044] 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.

[0045] The storage unit 12 stores a program for executing the processing described below and data required for executing the temperature calibration processing described below. One of the data includes "second correlation information between first difference information and second difference information, the first difference information being the difference between the measured value of the ambient temperature obtained by the concentration measuring device 1 and the measured value of the temperature of the calibration sample (disinfectant with known concentration), and the second difference information being the difference between the theoretical temperature and the temperature of the calibration sample, the theoretical temperature being obtained based on the first correlation information between the temperature and the transmittance of the calibration sample relative to the measured value of the transmittance of the calibration sample obtained by the concentration measuring device 1". This will be described in detail below.

[0046] 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 that performs calculations and has a CPU (Central Processing Unit) mounted thereon, such as a microcomputer.

[0047] The control / calculation unit 11 also functions as a temperature correction unit for performing the process described below, which is to "obtain 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, obtain corrected temperature information based on the second correlation information with respect to the difference information, and correct the measurement value obtained by the sample temperature sensor 131 according to the corrected temperature information."

[0048] Furthermore, the control unit also functions as a concentration calculation unit that calculates the concentration of the disinfectant based on the corrected temperature information of the disinfectant and the transmittance information of the disinfectant.

[0049] It should be noted that, although omitted in the figure, the control / calculation unit 11 can of course be connected to each part 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).

[0050] 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 be composed of hardware (for example, by a dedicated IC, etc.).

[0051] Next, refer to Figure 2 The concentration measurement method (mainly, the correction method of the measurement temperature) of this embodiment will be described.

[0052] Figure 2 This is a flowchart showing an outline of the concentration measurement method (mainly a method for correcting the measured temperature) of this embodiment. Flows 1 to 5 are the calibration process of the radiation temperature sensor 13 (setting of parameters for temperature correction) performed on each concentration measurement device 1 in the device manufacturing factory, and flows 6 to 8 are the process of concentration measurement (correction of the measured temperature for this purpose) in the concentration measurement device 1.

[0053] In process 1, first correlation information between temperature and transmittance is obtained based on a disinfectant (calibration sample) having a known concentration.

[0054] Specifically, a plurality of disinfectants of different concentrations whose concentrations 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°C, 15°C, 20°C, 25°C, 30°C, and 35°C, for example, by keeping the disinfectants in a constant temperature bath for a certain period of time.

[0055] Figure 3An example of a graph of the correlation between the temperature and transmittance of the disinfectant (calibration sample) thus obtained is shown in FIG. It should be noted that the concentration range of the disinfectant to be measured can be determined based on the concentration during actual use. Here, considering that the concentration of the disinfectant (product) as the target is 0.55% when it is new and the limit concentration for use is 0.3%, the measurement is performed within the range of 0.55 to 0.20%.

[0056] Next, find Figure 3 Approximate formula of the graph (function of concentration N, temperature T, and transmittance k).

[0057] The concentration N is calculated by the following formula 1 using the temperature T and the transmittance k.

[0058] (Formula 1) N=iT 2 k 2 +hTk 2 +gk 2 +fT 2 k+eTk+dk+cT 2 +bT+a It should be noted that a to i are coefficients.

[0059] In the following equation 2 obtained by transforming equation 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).

[0060] (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 square method, and coefficients a to i are calculated by the least square method based on the obtained A to C (quadratic functions of T).

[0061] Thus, we get Figure 3 The coefficients of Formula 1 are approximated by the graph.

[0062] It should be explained that Figure 3 Any of the information on the graphically graphed state (or information used therefor) and the information as an approximate formula obtained based thereon corresponds to the “first correlation information”.

[0063] The calculation process of the “first correlation information” is performed on an information processing device (a 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 .

[0064] 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 (disinfectant solution with a known concentration) are measured over time.

[0065] More specifically, a concentration measuring device 1 (optical cell OC) temperature-controlled at an ambient (surrounding) temperature (e.g., 15°C) and a calibration sample temperature-controlled at a temperature different therefrom (e.g., 30°C) are prepared, and the temperature, transmittance, and ambient temperature of the calibration sample are acquired over time using the concentration measuring device 1. Data is acquired on the process of the optical cell OC and the calibration sample placed therein gradually reaching thermal equilibrium, each with a different temperature. It should be noted that the temporal measurement is preferably performed until a state that can be regarded as a thermal equilibrium state (a state in which the temperature difference between the ambient temperature and the liquid temperature disappears) is reached.

[0066] 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).

[0067] The above processing of process 2 is performed under the condition that the ambient temperature (temperature of the concentration measuring device 1 (optical unit OC)) and the temperature of the calibration sample are different as described above, and the temperature is reversed (for example, the ambient temperature is 30°C and the temperature of the calibration sample is 15°C, which is the opposite of the above example). It should be noted that the setting of the ambient temperature and the temperature of the calibration sample can be set to the vicinity of the maximum value of the temperature difference that can be imagined 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 temperature of the calibration sample is 30°C ( Figure 4 (a)), 2. Ambient temperature 30°C, calibration sample temperature 15°C ( Figure 4 It should be noted that a slight difference in the concentration of the disinfectant will not have a significant effect on the behavior of thermal equilibrium, so 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 Flow 1), but here a disinfectant with a concentration of 0.3% as the use limit is used.

[0068] Figure 4 An example of the data obtained in process 2 is shown in FIG. objectis 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 the case where the liquid temperature is lower than the ambient temperature.

[0069] It should be noted that, here, T sub1 From T PTAT Subtract T object 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 necessary, and the difference in sign does not lead to any conceptual difference).

[0070] In process 3, the measured values ​​of the transmittance of the calibration sample measured over time using the concentration measuring device 1 in process 2 are subjected to a process of calculating the theoretical temperature based on the first correlation information.

[0071] That is, in the formula 1 as the first correlation information, the temperature T (theoretical temperature T ref ) processing.

[0072] Figure 5 The calculated theoretical temperature T ref An example after diagramming. Figure 5 (a) indicates the case where the liquid temperature is higher than the ambient temperature (when the liquid temperature gradually decreases during thermal equilibrium). Figure 5 (b) shows a case where the liquid temperature is lower than the ambient temperature (a case where the liquid temperature gradually rises due to thermal equilibrium).

[0073] 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 be configured to be executed on the concentration measurement device 1 .

[0074] 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.

[0075] Figure 6is 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 diagrammed figure. Figure 6 (a) indicates that the liquid temperature is higher than the ambient temperature. Figure 6 (b) indicates the case where the liquid temperature is lower than the ambient temperature.

[0076] Figure 7 The second difference information T sub2 Set as the Y axis, and set 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 the Y axis, and set the first difference information T sub1 As an example, the second difference information T sub2 Set as the X axis, the first difference information T sub1 Set as the Y-axis (there is no conceptual difference between the two).

[0077] In process 5, find Figure 7 Graph (second difference information T sub2 and the first difference information T sub1 The approximate formula of the function of .

[0078] In the present embodiment, exponential function approximation (calculation of coefficients a1, b1, c1) is performed based on equation (4).

[0079] (Formula 4) T sub2 =a1·e （b1·Tsub1） +c1 Figure 8 The figure which graphed the obtained approximate formula is shown in FIG. 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, c1 corresponding to negative second correlation information and coefficients a1, b1, c1 corresponding to positive second correlation information are obtained.

[0080] It should be explained that Figure 8Any of the information on the graphical state of (or information used therefor) and the information as an approximate formula obtained based thereon corresponds to the “second correlation information”.

[0081] 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 be configured to be executed on the concentration measurement device 1 .

[0082] The processing of the above-mentioned processes 1 to 5 is 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 (setting of parameters for temperature correction) of the radiation temperature sensor 13.

[0083] The concentration measurement of the disinfectant using the concentration measuring device 1 is performed by processing in Flow 6 to Flow 8. The concentration calculation process (Flow 8) itself can use a conventional method as it is, and the description is omitted here, and the correction of the measurement temperature of the disinfectant required for the concentration calculation will be mainly described.

[0084] The concentration measurement of a disinfectant (a sample with unknown concentration) using the concentration measuring device 1 is performed with the optical unit OC placed in the device and the disinfectant placed therein, based on the measurement of the temperature of the disinfectant by the sample temperature sensor 131, the measurement of the ambient temperature by the ambient temperature sensor 132, and the measurement of the transmittance of the disinfectant by the light emitting unit 141 and the light receiving unit 142.

[0085] In flow 6 , whether the positive or negative value is determined by subtracting the measured value of the temperature of the disinfectant obtained by the sample temperature sensor 131 from the measured value of the ambient temperature obtained by the ambient temperature sensor 132 .

[0086] If the result of this determination is negative, the processing of flows 7-1 and 8-1 is executed, and if it is positive, the processing of flows 7-2 and 8-2 is executed. It should be noted that here, 0 is processed as negative, but 0 may also be processed as positive.

[0087] In flow 7-1, the control / calculation unit 11 performs the following processing: a value (T sub1 ) into the approximate formula (4) (with Figure 8The negative second correlation information corresponding to (a)) is calculated as the temperature difference information (T sub2 ).

[0088] Then, the control / calculation unit 11 performs the following processing: by using (adding) the temperature difference information (T sub2 ), correct the measured value of the temperature of the disinfectant obtained by the sample temperature sensor 131.

[0089] 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.

[0090] 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, so the description is omitted.

[0091] Fig. 9 2 shows the concentration measurement results (the results of the verification experiment) of a disinfectant having a concentration of 0.3% using the concentration measurement device 1 .

[0092] To illustrate the effect of temperature correction obtained 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. Fig. 9 (a) indicates the case where the liquid temperature is higher than the ambient temperature (the liquid temperature at the start of the measurement is set to about 25°C and the ambient temperature is set to about 15°C). Fig. 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.).

[0093] In the graph, the dotted line shows the range of ±0.01 with respect to the concentration of 0.3% as the standard.

[0094] As shown in the figure, the concentration based on the temperature before correction is less than 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 the concentration is outside the range of ±0.01 relative to the disinfectant with an original concentration of 0.3% 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 from the start of measurement to about 45 seconds. That is, in the past, it was necessary to wait for a minimum amount of time before measurement (since it was impossible to accurately know how much time to wait, if safety is considered, a waiting time of at least 60 seconds is required).

[0095] 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.

[0096] It should be noted that immediately after the disinfectant is injected into the optical unit, the measured value may be unstable due to the movement of the liquid caused by the injection, the generation of bubbles, etc. (considered to be Fig. 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.

[0097] As described above, according to the concentration measuring device 1 and the method for correcting the measured temperature of the present embodiment, even when there is a temperature difference between the ambient temperature and the liquid temperature of the disinfectant, the temperature of the disinfectant can be accurately measured (corrected). Therefore, the waiting time required in the past until the ambient temperature and the liquid temperature of the disinfectant become the same can be shortened or eliminated, and the concentration can be measured in a short time.

[0098] Although it is a problem to accurately measure the temperature of the disinfectant when obtaining the calibration line for the correction, according to the present embodiment, the problem is solved by using the correlation between the temperature and transmittance of the disinfectant to obtain the liquid temperature (theoretical temperature) based on the transmittance. As a result, it is possible to obtain the correlation (i.e., the calibration line for correction) between the apparent temperature of the disinfectant obtained by the sensor (the wall temperature of the cell) and the value obtained by estimating the actual temperature of the disinfectant (theoretical temperature).

[0099] 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.

[0100] This is because different tendencies were observed in the direction of liquid temperature decrease and the direction of liquid temperature increase, so they were handled separately (in order to further improve accuracy). It is believed that this tendency is affected by the heat generated by the concentration measuring device as an electronic device. In other words, the heat generated by the light-emitting part and other electronic components during operation tends to be biased in the direction of increasing the liquid temperature, so it is believed that different tendencies (asymmetry) are generated in the direction of liquid temperature decrease and the direction of liquid temperature increase.

[0101] Therefore, 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 “second correlation information” without distinguishing between positive second correlation information and negative second correlation information.

[0102] Alternatively, by introducing a correction value for evaluating “offset due to the influence of heat or the like of the electronic component”, correction may be performed using only one “second correlation information” (the above-mentioned offset amount may be further corrected using the correction value).

[0103] In the case where 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 case of T in process 6 sub1 When the value is close to 0 (or less than a given 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 .

[0104] 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), error processing such as outputting an error message to the output unit 16 may be performed.

[0105] If the data is outside the range used for correction, it is treated as an error.

[0106] It should be noted that, instead of taking error action, the process may be performed to wait 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 ambient temperature measurement value and the sample temperature measurement value when the calibration sample is measured by thermal equilibrium.

[0107] Fig.10 An example of this processing is shown in FIG.

[0108] Fig.10 The treatment is to replace Figure 2As a prerequisite for this process, the T obtained by the process of process 2 is sub1 The absolute value of the maximum value (positive and negative) of is set in the concentration measuring device 1 (storage unit 12) as threshold values ​​1 and 2. For example, in the process of process 2, when the ambient temperature is 16°C and the temperature of the calibration sample is 29°C, 13°C is set as threshold value 1, and when the ambient temperature is 31°C and the temperature of the calibration sample is 15°C, 16°C is set as threshold value 2.

[0109] In step 901, a value (T = 0) is determined by subtracting the temperature of the disinfectant solution measured by the sample temperature sensor 131 from the ambient temperature measured by the ambient temperature sensor 132. sub1 )’s positive or negative.

[0110] If the result of the discrimination is negative, the processing of steps 902 and 903 is performed, and if the result of the discrimination is positive, the processing of steps 904 and 905 is performed. It should be noted that although 0 is set as negative processing, 0 may also be set as positive processing. In addition, as described above, the temperature correction processing may also be skipped in the case of 0.

[0111] In step 902, determine T sub1 The absolute value of exceeds the threshold value 1. If so, the output unit 16 displays a message such as “waiting until the liquid temperature reaches the measurable condition (or simply ‘measuring’)” (step 903). sub1 The loop processing of steps 902 to 903 is performed until the absolute value of becomes less than or equal to the threshold value 1.

[0112] In the determination of step 902, at T sub1 If the absolute value of is below the threshold value 1, the Figure 2 The process 7-1 is used for correction processing.

[0113] It should be noted that the processing of steps 904 and 905 when the result of the determination in step 901 is positive is the same as the processing of steps 902 and 903 except that threshold 2 is used instead of threshold 1, and therefore the description thereof is omitted.

[0114] It should be noted that in the embodiment, disinfectants such as glutaraldehyde aqueous solution and o-phthalaldehyde aqueous solution are used as examples as the measurement object of concentration, but the present invention is not limited to this and the concept of the present invention can be applied to any sample that has a correlation between temperature, transmittance or absorbance, and concentration.

[0115] In the embodiment, a non-contact temperature sensor, ie, a radiation temperature sensor, is used as an example of a temperature sensor, but the present invention is not limited thereto. For example, the concept of the present invention can be applied to a structure in which the temperature of the optical unit is measured by any temperature sensor such as a contact temperature sensor.

[0116] Furthermore, although the reference temperature sensor provided in the radiation temperature sensor is used as an example as the ambient temperature sensor for measuring the ambient temperature, the present invention is not limited thereto, and any temperature sensor capable of measuring the ambient temperature may be separately provided.

[0117] Explanation of symbols 1: Concentration measurement device 11: Control / calculation unit (temperature correction unit) 12: Storage 13: Radiation temperature sensor (sample temperature sensor, ambient temperature sensor) 141: Light emitting unit (optical sensor) 142: Light receiving part (optical sensor).

Claims

1. A method for calibrating the measurement temperature of a concentration measuring device, comprising the following steps: A step of obtaining first correlation information between temperature and transmittance or absorbance based on a sample with a known concentration; The step of measuring, over time, values ​​related to the temperature, transmittance or absorbance of a sample with a known concentration, and the ambient temperature by a concentration measuring device including 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 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 with a known concentration, wherein the theoretical temperature is obtained based on the first correlation information with respect to the measured value of the transmittance or absorbance; In the temperature measurement of a sample in the concentration measurement of a sample with unknown concentration, the step of obtaining difference information between a measured value of the temperature of the sample obtained by the sample temperature sensor and a measured value of the ambient temperature obtained by the ambient temperature sensor, and obtaining corrected temperature information obtained 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 positive or negative value 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 in accordance with the positive or negative 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 measured value of the ambient temperature and the measured value of the sample temperature when measuring the concentration of the sample with unknown concentration is greater than the absolute value of 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 sample with known concentration, it is considered an error.

4. A concentration measuring device for measuring the concentration of a sample having a correlation among temperature, 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 the ambient temperature obtained by the concentration measuring device and a measured value of the temperature of the calibration sample, and 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 the first correlation information between the temperature of the calibration sample and the transmittance or absorbance with respect to the measured value of the transmittance or absorbance of the calibration sample obtained by the concentration measuring device; and A temperature correction unit obtains difference information between a temperature measurement value of a sample obtained by the sample temperature sensor and a temperature measurement value of an ambient temperature obtained by the ambient temperature sensor, and corrects the measurement value obtained by the sample temperature sensor according to correction temperature information obtained based on the second correlation information with respect 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 is measured, The corrected temperature information is acquired based on either the positive second correlation information or the negative second correlation information in accordance with the positive or negative sign of the difference between the ambient temperature measured by the ambient temperature sensor and the sample temperature measured by the sample temperature sensor.

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

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