Calculation device for measuring instrument, measuring instrument, and measuring method

Abstract

To provide an arithmetic unit for a measurement instrument capable of performing measurement regardless of whether or not specific data stored in an RF tag are acquired successfully, a probe and a measurement method.SOLUTION: In an arithmetic unit 10 for a measurement instrument 1, an arithmetic processing section 12 executes measurement processing in which an output value Dt is outputted by correcting digital data Mt obtained by converting an analog signal Ad transmitted from a probe 20 based on correction data 30. Predetermined data 32 are previously stored in an auxiliary storage section 14, and a reader 33 executes data acquisition processing for acquiring specific data 31 stored in an RF tag 34 by communicating with the RF tag 34. In the executed measurement processing, in a case where the specific data 31 are acquired, the specific data 31 are used as the correction data 30 and in a case where the specific data 31 are not acquired, the predetermined data 32 are used as the correction data 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an arithmetic device for a measuring instrument and Measuring instrument and a measuring method, and more specifically, relates to an arithmetic device for a measuring instrument that measures a physical quantity of a measurement target using a probe in which a male connector of the probe is inserted into a female connector of the arithmetic device, and Measuring instrument and the measuring method.

Background Art

[0002] The output value indicating the physical quantity of the measurement target obtained by measurement using a measuring instrument (sensor) in which the probe and the arithmetic device are separate bodies includes a mechanical error caused by individual differences among the probes as a systematic error. This mechanical error is affected by differences in the production lots of the measuring elements provided in the probe, the manufacturing accuracy of the probe, and further changes in the physical quantity of the measurement object due to measurement using the probe, and varies from probe to probe. As a method for eliminating this mechanical error, for example, there is a method in which a probe and a storage medium are set as a set, unique data for eliminating the mechanical error of the probe is stored in the storage medium, the arithmetic device is caused to acquire the unique data, and correction is performed using the unique data. By using this method, it becomes possible to eliminate the mechanical error that differs for each probe.

[0003] As for the storage medium, although it is not an invention related to a measuring instrument, various RF (Radio Frequency) tags (electronic tags, wireless tags, IC tags, RFID tags) provided on electric cables of electronic devices have been proposed (see Patent Document 1). The probe of the measuring instrument is provided with the RF tag proposed in Patent Document 1, and the arithmetic device of the measuring instrument is provided with a reader that acquires the unique data stored in the RF tag, whereby the mechanical error that differs for each probe can be eliminated very easily.

[0004] However, management systems incorporating RFID (Radio Frequency Identifier) ​​systems using RF tags and readers assume that all objects to be managed (for example, the electric wires and cables in Patent Document 1) are equipped with RF tags. Therefore, objects that do not have RF tags, or objects that have RF tags but whose data cannot be acquired by the reader, are not subject to management. In other words, in measuring instruments incorporating RFID systems, if the probe does not have an RF tag, or if the probe has an RF tag but the reader cannot acquire unique data from that RF tag, it is not possible to perform correction using unique data. As a result, it becomes impossible to output an output value, leading to a situation where measurement is not possible. Thus, even if an existing RFID system is incorporated into a measuring instrument, there is room for improvement in order to perform measurements regardless of the success or failure of acquiring unique data. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-17142 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of the present invention is a computing device for a measuring instrument that can measure regardless of whether or not it is successful in acquiring unique data stored in an RF tag. Measuring instrument Furthermore, the objective is to provide a measurement method. [Means for solving the problem]

[0007] The present invention provides a measuring instrument arithmetic device that achieves the above objective, comprising an arithmetic processing unit, a storage unit, a female connector, and a reader, wherein the male connector of a probe is detachably inserted into the female connector, and the arithmetic processing unit and the probe are electrically connected, wherein the arithmetic processing unit performs a measurement process in which digital data obtained by converting an analog signal transmitted from the probe is corrected by correction data, and an output value indicating the physical quantity of the object to be measured is output, the storage unit has default data stored in advance, and the reader performs a data acquisition process in which unique data stored in the RF tag of the probe connected to the arithmetic processing unit is acquired by communication with the RF tag of the probe before the measurement process is executed, and in the executed measurement process, if the unique data is acquired in the data acquisition process, the unique data is used as the correction data, and the output value in which the mechanical error of the probe is eliminated is output, and if the unique data is not acquired, the default data is used as the correction data, and the output value including the mechanical error of the probe is output.

[0008] Measurement of the present invention The vessel is , the calculation device of the above measuring instrument and the aforementioned computing device Electrically connected to 、 The RF tag having the aforementioned unique data stored in it A probe and, It is characterized by the following:

[0009] The measurement method for the measuring instrument of the present invention involves electrically connecting the arithmetic processing unit of the arithmetic processing unit and the probe by detachably inserting the male connector of the probe into the female connector of the arithmetic processing unit, wherein the reader of the arithmetic processing unit communicates with the RF tag of the probe connected to the arithmetic processing unit and performs a data acquisition step to acquire unique data stored in the RF tag in which the mechanical error of the probe is known in advance, and then the arithmetic processing unit converts the analog signal transmitted from the probe to obtain digital data, Calculation unitA measurement step is performed in which an output value indicating the physical quantity to be measured is output by correcting based on data stored at a predetermined memory address in the storage unit, and in the measurement step, if the unique data is acquired in the data acquisition step, that unique data is used as the data, and if the unique data cannot be acquired, default data that is pre-stored in the storage unit and does not take into account the mechanical error of the probe is used as the data. [Effects of the Invention]

[0010] According to the present invention, by changing the data used in the measurement process depending on whether or not the unique data stored in the RF tag can be acquired, the data processing until the output value is output can be completed without interruption even if the unique data stored in the RF tag cannot be acquired. As a result, the present invention enables measurement using probes without RF tags, while using an RFID system when measuring with probes equipped with RF tags makes it possible to achieve highly accurate measurement that eliminates mechanical errors that differ for each probe in a very simple manner. [Brief explanation of the drawing]

[0011] [Figure 1] This is a diagram illustrating an example of the calculation unit and the measuring instrument itself. [Figure 2] Figure 1 is a perspective view illustrating the female connector of the computing device and the male connector of the probe. [Figure 3] Figure 1 is a diagram illustrating the configuration in which the male connector of the probe is inserted into the female connector of the computing device. [Figure 4] This is an explanatory diagram illustrating the correction data used in the measurement process. [Figure 5] This graph illustrates the relationship between the reference values ​​and calibration values ​​for both unique data and default data. [Figure 6] This is a flowchart illustrating the steps of an embodiment of the measurement method for a measuring instrument. [Figure 7] This is a flowchart illustrating the measurement process shown in Figure 6. [Figure 8] It is a graph illustrating an example of the error in the measurement results of the embodiment. [Mode for Carrying Out the Invention]

[0012] Hereinafter, the arithmetic device of the measuring instrument and Measuring instrument as well as the measurement method will be described based on the embodiment shown in the drawings.

[0013] The measuring instrument (sensor) 1 illustrated in FIG. 1 includes an arithmetic device 10 and a probe 20 which are separate from each other, and various known digital sensors that quantify the physical quantity of a measurement target using scientific principles can be used. Examples of physical quantities that can be quantified by the measuring instrument 1 include mechanical properties, electromagnetic properties, thermal properties, acoustic properties, chemical properties, spatial information, and temporal information. For example, the measuring instrument 1 is a thermocouple temperature sensor that quantifies temperature as a physical quantity using the Seebeck effect as a scientific principle.

[0014] The embodiment of the arithmetic device 10 includes a housing 11, an arithmetic processing unit 12, a main storage unit 13, an auxiliary storage unit 14, a display 15, an external bus connector 16, a female connector 17, a power switch 18, and a reader 33. The arithmetic device 10 corrects the digital data Mt obtained by converting the analog signal Ad detected by the probe 20 with the data 30 (hereinafter referred to as correction data) stored at a predetermined memory address in the main storage unit 13, and outputs an output value Dt indicating the physical quantity of the measurement target. Each of the main storage unit 13 and the auxiliary storage unit 14 corresponds to a storage unit. The arithmetic device 10 is a portable type that operates with power supplied from a portable power source (for example, a dry battery), but may be a stationary type that operates with power supplied from a commercial power source. Various known computers can also be used as the arithmetic device 10.

[0015] The housing 11 accommodates therein an arithmetic processing unit 12, a main storage unit 13, an auxiliary storage unit 14, and a reader 33, and is provided with a display 15, an external bus connector 16, a female connector 17, and a power switch 18 on its exterior as an output unit and an input unit. The material constituting the housing 11 is not particularly limited, but it is desirable that at least the periphery of the installation location of the reader 33 is made of a material that hardly causes interference with magnetic force and radio waves. Examples of such a material include synthetic resins.

[0016] The arithmetic processing unit 12 may have any configuration as long as it can execute each data processing up to outputting the output value Dt, and various known processors can be used. In addition to the processor, the arithmetic processing unit 12 may include known electronic circuits such as a multiplexer and a compensator. In the thermocouple temperature sensor, the arithmetic processing unit 12 includes, as a compensator, a reference junction compensator that uses the female connector 17 as a reference junction.

[0017] For the main storage unit 13, various known RAMs (Random Access Memory) can be used. A predetermined address is designated in the main storage unit 13 as an area for correction data 30 used in a series of data processing executed by the arithmetic processing unit 12. For the auxiliary storage unit 14, various known ROMs (Read Only Memory) can be used. The auxiliary storage unit 14 is not limited to one accommodated inside the housing 11, and an external storage device such as a flash memory may be used. Preset data 32 is stored in advance in the auxiliary storage unit 14. For the display 15, various known video display devices can be used. For the external bus connector 16, various known serial bus or parallel bus connectors can be used.

[0018] The female connector 17 is a connector into which the male connector 24 of the probe 20 is detachably inserted, and a known female receptacle can be used. The female connector 17 may use a known female adapter attached to the end of the wire leading out from the housing 11, but it is preferable to use a female receptacle considering the installation of the antenna base 35 of the reader 33, which will be described later. The female connector 17 has a space that is recessed from the outside to the inside of the housing 11, and a plurality of male contacts (pin inserts) 19 are housed in this space. The plurality of male contacts 19 are pin terminals that protrude from the outside to the inside of the housing 11 and are connected to each wire led out from the arithmetic processing unit 12. The number of male contacts 19 is the same as the number of signals transmitted and received between the arithmetic processing unit 12 and the probe 20, and in the case of a thermocouple thermometer, there are two. The male contacts 19 are housed in the female connector 17 without their tips protruding outward from the female connector 17.

[0019] The reader 33 can use a reader from a known RFID (Radio Frequency Identifier) ​​system. The reader 33 has a separate antenna board 35 and a controller board 36. The surface of the antenna board 35 faces the multiple male contacts 19 in a direction (e.g., Z direction) that intersects the insertion / removal direction (X direction) of the male connector 24. The controller board 36 is connected to the arithmetic processing unit 12 and the antenna board 35 via signal lines. The controller board 36 performs the data acquisition process described later according to the instructions of the arithmetic processing unit 12. Note that the antenna board 35 and the controller board 36 of the reader 33 may be integrated. Also, although the reader 33 has only a reading function, it may also have a writing function.

[0020] The embodiment of the probe 20 includes a measuring element 21, a probe body 22, a cable 23, a male connector 24, and an RF tag 34. The probe 20 detects the physical quantity of the object to be measured as an analog signal Ad by the measuring element 21 and transmits the detected analog signal Ad to the computing device 10. The probe 20 is exemplified as a passive type in which the measuring element 21 directly receives the physical quantity of the object to be measured, but it may also be an active type that transmits a predetermined signal to the object to be measured and receives the reflection of the transmitted signal. In a thermocouple temperature sensor, the probe 20 is an active type that uses a thermocouple as the measuring element 21.

[0021] The measuring element 21 can be any known measuring element. For example, the measuring element 21 for measuring temperature can be a thermocouple, a platinum resistor, or a thermistor. In a thermocouple temperature sensor, the measuring element 21 is a thermocouple, which consists of two different types of metal wires, and detects the voltage of the electromotive force generated at the junction of these wires, the measuring section 25, as an analog signal Ad. Examples of thermocouples include Type K, which uses Chromel for the + electrode and Alumel for the - electrode; Type E, which uses Chromel for the + electrode and Constantan for the - electrode; and Type B, which uses a platinum-rhodium alloy (rhodium content 30%) for the + electrode and a platinum-rhodium alloy (rhodium content 6%) for the - electrode.

[0022] The probe body 22 and cable 23 are not particularly limited. For example, in the probe body 22 of a passive probe 20, a measuring element 21 is housed inside, and a measuring section 25, which is the junction point between dissimilar metal wires of the measuring element 21, is located at its tip. The cable 23 is constructed by covering either the measuring element 21 led out from the probe body 22 or a separate wire that transmits signals from the measuring element 21 with a covering material.

[0023] The male connector 24 is a connector that is detachably plugged into the female connector 17 of the arithmetic unit 10 and is attached to the end of the cable 23. A known male plug can be used for the male connector 24. The male connector 24 has multiple female contacts (socket inserts) 26 embedded in its end. The multiple female contacts 26 are socket terminals into which each of the multiple male contacts 19 is inserted and are electrically connected to the cable 23. The number of female contacts 26 is the same as the number of signals transmitted and received between the arithmetic processing unit 12 and the probe 20, and in the case of a thermocouple temperature sensor, there are two. The ends of the female contacts 26 are housed in the male connector 24 without protruding outward from the male connector 24.

[0024] The RF tag 34 can be any known RF (Radio Frequency) tag (electronic tag, wireless tag, IC tag, RFID tag) from an RFID system. The RF tag 34 is made up of a single substrate. It is desirable that the RF tag 34 be placed on the outer surface of the portion of the male connector 24 that is inserted into the female connector 17. The RF tag 34 is embedded in a hole that is recessed inward from the outer surface of the male connector 24. The embedded RF tag 34 does not need to have its surface exposed to the outer surface of the male connector 24, but it is desirable that it be exposed to ensure the strength of the communication.

[0025] An RFID system consisting of a reader 33 and an RF tag 34 uses wireless communication to obtain unique data 31 stored in the RF tag 34 via the reader 33. Examples of frequency bands for RFID systems include long waves (LF) below 135 kHz, short waves (HF) at 13.56 MHz, and ultra-high frequency (UHF) at 433 MHz or 860 MHz to 960 MHz or 2.45 GHz. Depending on the frequency band, RFID systems use communication methods (spatial transmission methods) such as electromagnetic coupling, electromagnetic induction, and radio wave methods.

[0026] It is desirable that the RFID system uses either long-wave or short-wave frequency bands. If the RFID system uses long-wave or short-wave frequency bands, the reader 33 on the computing unit 10 and the RF tag 34 on the probe 20 can communicate one-to-one only, and only at close range (10 cm or less), which is advantageous in avoiding the acquisition of unnecessary data (data other than the unique data 31). In addition, RFID systems using long-wave or short-wave frequency bands are less expensive than RFID systems using ultra-high frequency bands, which is advantageous in reducing the cost required for implementation.

[0027] Figure 2 shows the state before inserting the male connector 24 into the female connector 17, and Figure 3 shows the state after inserting the male connector 24 into the female connector 17. When the male connector 24 is inserted into the female connector 17, the male contact 19 is inserted into the female contact 26 and electrically connected. Both the female connector 17 and the male connector 24 are keyed; the female connector 17 has a groove formed that is recessed from the internal space outward, and the male connector 24 has a protrusion that extends outward from the outer surface and fits into the groove. The keying of the male connector 24 is applied to the area where the RF tag 34 is not installed.

[0028] A reader antenna 37 is formed on the antenna base 35. Various known antennas can be used for the reader antenna 37. It is desirable that the reader antenna 37 faces the tag antenna 38 of the RF tag 34 when the male connector 24 is inserted into the female connector 17. In RFID systems with long wave or short wave frequency bands, the direction of the magnetic field generated by the reader antenna 37 is oriented in a direction (Z direction) that intersects the insertion / removal direction (X direction) of the male connector 24 of the probe 20. It is desirable that the direction of the magnetic field generated by the reader antenna 37 is perpendicular to the surface of the RF tag 34 installed in the part of the male connector 24 that is inserted into the female connector 17. It is also desirable that the reader antenna 37 be positioned towards the center of the housing 11 when viewed in the X direction. By positioning the reader antenna 37 towards the center of the housing 11, the housing 11 occupies a portion of the wireless communication range of the reader antenna 37, which is advantageous in avoiding the acquisition of unnecessary data (data other than the unique data 31). Furthermore, it is desirable that the reader antenna 37 be larger than the RF tag 34, and that its center be located at the center of the RF tag 34 when the male connector 24 is inserted into the female connector 17.

[0029] The RF tag 34 incorporates a tag antenna 38 and a memory 39. Similar to the reader antenna 37, various known antennas can be used for the tag antenna 38. The memory 39 is connected to the tag antenna 38 via a signal line and stores unique data 31. This unique data 31 is pre-defined data and is written to the memory 39 using the RFID system's writer.

[0030] The correction data 30 shown in Figure 4 is either unique data 31 or default data 32 stored at a predetermined memory address in the main memory unit 13, and each data is swapped depending on whether or not the unique data 31 has been acquired. The correction data 30 is an accumulation of multiple pairs of reference values ​​(F1, ..., Fn) and calibration values ​​(S1, ..., Sn) in the same row of the table. The reference values ​​and calibration values ​​are arranged in descending order of numerical value, and in the table in Figure 4, the numerical values ​​increase from top to bottom in the columns. In the table in Figure 4, the specific values ​​of the reference values ​​and calibration values ​​are abbreviated with "...", but in reality, the numerical values ​​are written. The mechanical error (E1, ..., En) listed outside the table indicates the difference between the reference value and calibration value in the same row of the table and is not included in the actual correction data 30. This mechanical error is influenced by differences in the manufacturing lots of the measuring element 21, the manufacturing precision of the probe body 22, and changes in the physical quantity of the object being measured that occur when the probe 20 is in direct contact with the object (for example, if the physical quantity is temperature, the change in temperature due to heat transfer caused by contact with the probe 20). Therefore, this mechanical error differs for each probe 20 and is an error that is difficult to predict in advance during the design and manufacturing process of the probe 20.

[0031] The unique data 31 and the default data 32 have the same data structure as the correction data 30, but they differ in whether or not they can eliminate the mechanical error of the probe 20. The unique data 31 is calibrated using the calibration results of the measuring instrument 1, and the mechanical error of the probe 20 is known in advance. It is data that can reduce this mechanical error and approximate the output value Dt to the true value. In addition, the unique data 31 may have some of the mechanical errors shown in Figure 4 as "0", but it is not data in which all of them are "0". The default data 32 is arbitrarily created to match the data structure of the unique data 31, and it is data in which the mechanical error of the probe 20 is not known. In addition, the default data 32 is data in which all of the mechanical errors (E1~En) shown in Figure 4 are "0". The unique data 31 and the default data 32 will be described in detail below.

[0032] The unique data 31 and default data 32 illustrated in Figure 5 are obtained by setting the measurable range of the measuring instrument 1 to -100 to 100 (units omitted), setting the intervals between reference values ​​to equal intervals of 50 in the positive range and equal intervals of -30 in the negative range, and setting n=6. The intervals between the respective reference values ​​(or calibration values) of the unique data 31 and default data 32 may be unequal, but it is desirable that the smallest reference value (F1) is located near the minimum value of the measurable range of the measuring instrument 1 (the range in which nominal accuracy can be guaranteed), and the largest reference value (F6) is located near the maximum value of the measurable range. Furthermore, when the intervals are unequal, it is desirable that the unique data 31 indicates each of the nonlinear inflection points in the graph.

[0033] The unique data 31 is a collection of multiple sets (n sets) of reference values ​​obtained from measurements using a reference measuring instrument and calibration values ​​obtained from measurements using measuring instrument 1, utilizing various known calibration methods using a reference measuring instrument different from measuring instrument 1. The unique data 31 exhibits a non-linear relationship between the change in the calibration value and the change in the reference value. The reference measuring instrument is not particularly limited as long as its systematic errors, including mechanical errors, are known in advance and the reference value obtained from the measurement approximates the true value, but it is more preferable to use one that employs a different scientific principle than measuring instrument 1. The reference value is measured by the reference measuring instrument and has a small error relative to the true value of the physical quantity being measured, and is a value that approximates the true value. The calibration value is measured by measuring instrument 1 with the probe 20 connected to the calculation unit 10 (however, the default data 32 is used as the correction data 30 in this measurement). The reference value and calibration value may be the average or median of multiple values ​​obtained by taking multiple measurements under the same conditions in which the physical quantity being measured and the measurement environment are standardized.

[0034] In known calibration methods, the physical quantity to be measured is gradually changed, and the changed physical quantity is measured using both the reference measuring instrument and measuring instrument 1. The difference (systematic error) between the reference value obtained from the measurement with the reference measuring instrument and the calibration value obtained from the measurement with measuring instrument 1 is brought as close to "zero" as possible. However, it is impossible to make the difference between the reference value and the calibration value "zero" over the entire range in which the physical quantity to be measured is changed unless the relationship between the reference value and the calibration value is perfectly linear. As a result, the difference between the reference value and the calibration value, which is the final calibration result, remains as an uncalibrated systematic error. In particular, the probe 20 is an analog circuit, and adjustment after manufacturing is not easy. Such an uncalibrated systematic error can generally be considered as a mechanical error of the probe 20. Thus, by using known calibration methods, it becomes possible to understand the mechanical error of the probe 20. The unique data 31 is data in which the reference value and calibration value, which are the final calibration results of the known calibration method, are stored in the memory 39 of the RF tag 34 using the RFID system's writer.

[0035] The mechanical error of the probe 20 within the measurable range of the measuring instrument 1 can be linear or nonlinear. If the mechanical error is linear, the unique data 31 only needs to consist of two sets of reference values ​​and calibration values ​​(n=2) within the measurement range. If the mechanical error is nonlinear, the unique data 31 only needs to consist of a number of reference values ​​and calibration values ​​that allow the measurement range to be discretized (excluding bisection) and the mechanical error to be expressed as a discretized continuous function. However, while a larger number of sets is advantageous for eliminating the mechanical error of the probe 20, it also increases the amount of information. In particular, there may be limitations on the amount of information that can be used for unique data 31 when using an RFID system. Therefore, it is desirable that the number of sets be within the amount of information that can be used by the RFID system. The amount of information that can be used by the RFID system is limited by the capacity of the memory 39 of the RF tag 34 and the amount that can be transmitted and received by the RFID system. The number of sets of unique data 31 can be appropriately selected based on the desired mechanical error correction accuracy and the amount of information that can be used by the RFID system.

[0036] The default data 32 is a collection of multiple sets (n sets) of reference values ​​and calibration values, arbitrarily created so that the difference is "0" in any set, in accordance with the data structure of the unique data 31 (for example, n=6). In the default data 32, the change in calibration value in response to a change in reference value is equal. In other words, the default data 32 is data that does not change the relationship between the digital data Mt and the output value Dt, and when the digital data Mt is corrected with the default data 32, the output value Dt does not change from the original digital data Mt.

[0037] Figures 6 and 7 show an example of the measurement method. First, when the power switch 18 is operated by the operator and the arithmetic unit 10 is started, the arithmetic processing unit 12 executes each data processing (S110 to S160). The measurement process (S160) is performed at predetermined intervals until the measurement is completed. Finally, when the measurement is completed (S170), the process ends. In the case of an arithmetic unit 10 that does not have a power switch 18, the arithmetic unit 10 is started when the power connector is plugged into the commercial power supply. The contents of each step (S110) to (S170) are described in detail below.

[0038] In the step of determining whether or not an operation on the measuring instrument 1 has been detected (S110), the calculation processing unit 12 determines whether or not the operation on the measuring instrument 1 by the operator has initiated the supply of power to an electrical circuit or to an electronic device through an electrical connection. Examples of such operations include the operator operating the power switch 18 or the operator inserting the male connector 24 of the probe 20 into the female connector 17 of the calculation unit 10. Detection of insertion is possible if the calculation processing unit 12 has a line-out detection circuit. If the calculation unit 10 or the probe 20 has a measurement switch for starting the measurement process (S160), the operation of the measurement switch by the operator may be detected. Note that when the operation on the measuring instrument 1 involves inserting the male connector 24 of the probe 20 into the female connector 17 of the calculation unit 10, the operator must perform the insertion operation after the calculation unit 10 has been started up.

[0039] In the defaultization process (S120), when the arithmetic processing unit 12 determines that an operation has been detected on the measuring instrument 1 (S110: YES), it saves the default data 32 stored in the auxiliary storage unit 14 to a predetermined memory address in the main storage unit 13 designated as the area for correction data 30. At this time, if other data is already stored in the predetermined memory address in the main storage unit 13, that data is overwritten with the default data 32.

[0040] In the data acquisition process (S130), the arithmetic processing unit 12 instructs the reader 33 to perform the data acquisition process. The reader 33 then initiates communication with the RF tag 34 and acquires the unique data 31 stored in the RF tag 34. This data acquisition process is performed regardless of whether the probe 20 has an RF tag 34, and is performed even if the probe 20 does not have an RF tag 34. Some readers in known RFID systems communicate with RF tags at all times, but this communication consumes power. Therefore, limiting the communication between the reader 33 and the RF tag 34 to predetermined timings by the arithmetic processing unit 12 is advantageous in reducing the power required for communication.

[0041] In the step of determining whether or not unique data 31 has been acquired (S140), the arithmetic processing unit 12 determines whether or not the reader 33 has acquired unique data 31 as a result of the data acquisition process (S130). Cases in which unique data 31 cannot be acquired include when the probe 20 does not have an RF tag 34, or when the probe 20 has an RF tag 34 but there is a communication failure or equipment failure in the RFID system. If it is determined that unique data 31 has been acquired (S130: YES), the process proceeds to the data storage process (S150), and if it is determined that unique data 31 has not been acquired (S130: NO), the process proceeds to the measurement process (S160).

[0042] In the data saving step (S150), the arithmetic processing unit 12 overwrites the unique data 31 acquired by the reader 33 with a predetermined memory address in the main memory unit 13 designated as the area for correction data 30 and saves it. Although default data 32 is saved in the predetermined memory address by the defaulting step (S120), the unique data 31 is saved in the predetermined memory address by this data saving step (S150). Alternatively, the unique data 31 acquired by the reader 33 may be saved in the auxiliary storage unit 14 before being saved in the predetermined memory address in the main memory unit 13.

[0043] In the measurement process (S160) shown in Figure 7, the arithmetic processing unit 12 executes each data processing step (S162 to S166) as part of the measurement process. Specifically, as the arithmetic processing unit 12 executes each data processing step, the digital data Mt obtained by converting the analog signal Ad is corrected by the correction data 30, and the output value Dt is output. The measurement process (S160) is repeated at predetermined intervals, and the output value Dt is output as needed.

[0044] In the step of converting the analog signal Ad to digital data Mt (S162), the arithmetic processing unit 12 converts the analog signal Ad transmitted from the probe 20 to digital data Mt representing the physical quantity of the object to be measured using a known conversion method. The conversion method only needs to be able to convert the numerical data of the analog signal Ad to digital data Mt representing the physical quantity of the object to be measured, and one that is appropriate for the measuring element 21 and the physical quantity of the object to be measured is used. Depending on the conversion method, the arithmetic processing unit 12 can use conversion data such as compensation values ​​output from a compensator, conversion tables, and conversion formulas that have been previously stored in the auxiliary storage unit 14. For example, in a thermocouple temperature sensor, the analog signal Ad is the voltage of the electromotive force of the thermocouple, which is the measuring element 21, and the digital data Mt represents the temperature of the object to be measured. To convert from the voltage of the electromotive force to digital data Mt representing the temperature, compensation values ​​obtained from a reference junction compensator or a standard thermoelectric power table specified in the Japanese Industrial Standard (JIS R 1602) can be used. Instead of the standard thermoelectric power table of the Japanese Industrial Standards (JIS), a temperature conversion polynomial using the thermocouple table of the National Bureau of Standards (NBS) may be used. The standard thermoelectric power table and thermocouple table differ depending on the type of thermocouple, and thermocouple temperature sensors have multiple standard thermoelectric power tables and thermocouple tables available, which are switched depending on the type of thermocouple. In this way, when the measuring element 21 is classified into multiple types, it is good practice to prepare multiple conversion data sets according to the type.

[0045] In the step of correcting the digital data Mt with correction data 30 (S164), the arithmetic processing unit 12 corrects the digital data Mt using a known interpolation method (interpolation method) with the correction data 30 and calculates the output value Dt. The correction data 30 is swapped between unique data 31 and default data 32 depending on whether unique data 31 has been acquired or not. More specifically, the correction data 30 becomes unique data 31 when the data storage process (S150) is performed, and becomes default data 32 saved from the defaultization process (S120) when the data storage process (S150) is not performed. The interpolation method can be any method that can eliminate the mechanical error of the probe 20 when unique data 31 is used as the correction data 30, and examples include linear interpolation (first-order interpolation), polynomial interpolation such as Newton interpolation and Lagrangian interpolation, piecewise linear interpolation (spline interpolation), and radial basis function (RBF) interpolation.

[0046] In step S166, which outputs the output value Dt, the calculation processing unit 12 displays the calculated output value Dt on the display 15 and stores it in the auxiliary storage unit 14. The calculated output value Dt may be displayed only on the display 15, or it may be stored only in the auxiliary storage unit 14. In this step, it is desirable for the calculation processing unit 12 to perform data processing that makes it possible to distinguish whether the unique data 31 or the default data 32 was used as the correction data 30. For example, when displaying the output value Dt on the display 15, a mark or something similar is displayed that makes it possible to distinguish whether the unique data 31 or the default data 32 was used as the correction data 30. Also, when storing the output value Dt in the auxiliary storage unit 14, data that makes it possible to distinguish whether the unique data 31 or the default data 32 was used as the correction data 30 is stored together with the output value Dt. By performing such data processing, if a reading error of the unique data 31 occurs in the RFID system, it becomes possible to correct the output value Dt output using the default data 32 as the correction data 30 after the measurement is completed. Furthermore, in measurements using a probe 20 that does not have an RF tag 34, if unique data 31 is unintentionally read from the RF tag 34 of another probe 20, it becomes possible to correct the output value Dt output using the unique data 31 as correction data 30 after the measurement is completed.

[0047] In the step of determining whether the measurement has finished (S170), the determination of the end of the measurement is made by either the operator or the arithmetic processing unit 12. The operator determines the end of the measurement when the power switch 18 is operated by the operator and the arithmetic unit 10 stops. Alternatively, the operator may also determine the end of the measurement when they operate the measurement switch. The arithmetic processing unit 12 determines the end of the measurement when a preset measurement period has elapsed or when the number of measurements has been reached.

[0048] As described above, according to this embodiment, depending on whether the reader 33 succeeds in acquiring the unique data 31 stored in the RF tag 34, the data used as correction data 30 is swapped between the unique data 31 and the default data 32. Therefore, if the unique data 31 stored in the RF tag 34 cannot be acquired, the default data 32 is used as the correction data 30, allowing the data processing until the output value Dt is output to be completed without interruption.

[0049] Furthermore, according to this embodiment, the data of the final calibration result is used as the unique data 31. Therefore, the output value Dt output using the unique data 31 as the correction data 30 has a smaller mechanical error in the non-calibrable probe 20 and is easier to approximate to the true value. As described above, this embodiment has a configuration that enables measurement using a probe without an RF tag 34, and when measuring with a probe 20 equipped with an RF tag 34, it is possible to achieve highly accurate measurement that eliminates the different mechanical errors for each probe 20 in a very simple way by using an RFID system.

[0050] Furthermore, according to this embodiment, there is no need to set the calculation unit 10 and the probe 20 together. Therefore, multiple probes 20 can be used with a single calculation unit 10. Moreover, if the connectors and other specifications are the same, the probes 20 can be connected to a calculation unit that was previously used for measurement, or the probes that were previously used can be connected to the calculation unit 10 for measurement. In this way, by making it possible to utilize existing assets, the cost of implementation can be reduced.

[0051] Although embodiments of the present invention have been described above, the calculation device, probe, and measurement method of the measuring instrument of the present invention are not limited to specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention.

[0052] In the step of converting the analog signal Ad to digital data Mt (S162), the digital data Mt may be data that is a numerical representation of the analog signal Ad. When the digital data Mt is data that is a numerical representation of the analog signal Ad, that is, a numerical value that does not directly represent the physical quantity of the object being measured, the unique data 31 has conversion data that converts the analog signal Ad to a numerical value that represents the physical quantity of the object being measured, and data that can eliminate the mechanical error of the probe 20. The default data 32 has only conversion data that converts the analog signal Ad to a numerical value that represents the physical quantity of the object being measured. In this way, because the unique data 31 and default data 32 have conversion data, in the step of correcting the digital data Mt with correction data 30 (S164), it becomes possible to calculate the output value Dt by correcting the data that is a direct numerical representation of the analog signal Ad with the correction data 30. However, the amount of information in the correction data 30 must match the amount of information in the unique data 31 and default data 32, respectively. Since the unique data 31 used in the RFID system has a limited amount of information, it is advisable to determine whether or not to add conversion data to the unique data 31 according to that limitation. Having conversion data in the unique data 31 eliminates the need for the arithmetic unit 10 to select a predetermined conversion data from multiple conversion data sets corresponding to the type of measurement element 21. This is advantageous in preventing erroneous measurements due to errors in the selection of conversion data by the arithmetic unit 10.

[0053] In the step (S110) of determining whether or not an operation on the measuring instrument 1 has been detected, it is preferable to detect multiple operations on the measuring instrument 1 by the operator, rather than limiting it to just one. For example, by detecting two operations, such as the operation of the power switch 18 and the connection operation of the arithmetic unit 10 and the probe 20, it becomes possible to change the probe 20 to a different probe during measurement.

[0054] The order of the defaultization process (S120) and the data acquisition process (S130) is not limited to the data acquisition process starting after the defaultization process, and the start of the data acquisition process is not limited to being signaled by the completion of the defaultization process. For example, if the usage is limited to the operation of the power switch 18 to start the arithmetic unit 10 and then connecting the probe 20 to the arithmetic unit 10, the start of the defaultization process may be signaled by the operation of the power switch 18, and the start of the data acquisition process may be signaled by the connection of the probe 20 to the arithmetic unit 10.

[0055] The correction data 30 may be stored in a predetermined memory address of the auxiliary storage unit 14. In this case, during the defaulting step and the data acquisition step, data 31 specific to the auxiliary storage unit 14 and default data 32 are stored in the predetermined memory address of the auxiliary storage unit 14. Then, during the measurement step, the correction data 30 stored in the predetermined memory address of the auxiliary storage unit 14 is written to a predetermined memory address of the main storage unit 13, and the output value Dt is calculated. Note that the data stored in the main storage unit 13 is erased when the arithmetic unit 10 stops.

[0056] The measuring instrument 1 connects the calculation unit 10 and the probe 20, and is ready for measurement work from the moment the calculation unit 10 is started. However, it is desirable that the measurement work be performed after the processing up to the moment immediately preceding the measurement process (S160) is completed. Therefore, when the processing up to the moment immediately preceding the measurement process is completed, a signal to start the measurement work may be displayed on the display 15 of the calculation unit 10.

[0057] As an example of the application of the present invention, there is a configuration in which a plurality of unique data 31 are pre-stored in the auxiliary storage unit 14, each of the plurality of unique data 31 is assigned a different identification number for each probe 20, and the RF tag 34 stores that identification number. In this configuration, in the data acquisition step (S130), the identification number is acquired instead of the unique data 31, the unique data 31 assigned the acquired identification number is identified from among the plurality of unique data 31 stored in the auxiliary storage unit 14, and in the data storage step (S150), the identified unique data 31 is overwritten at a predetermined memory address. In this application example, it is necessary to set the probe 20 and an electronic storage medium (such as a USB memory or flash memory) together and store the unique data 31 assigned an identification number from the electronic storage medium to the auxiliary storage unit 14 of the computing device 10. [Examples]

[0058] A prototype measuring device and probe were fabricated using a passive thermocouple temperature sensor with a Type K thermocouple as the measuring element and a probe in direct contact with the object being measured. This sensor incorporates an RFID system with a shortwave (HF) frequency band and a communication range of 10 cm, as illustrated in Figures 1 to 3. The measured range of the prototype measuring device was -100.00°C to 200.00°C.

[0059] In the measurement process using the prototype measuring instrument, the value obtained by subtracting the compensation value Rt [μV] obtained from the reference junction compensator from the detected value Vt [μV], which is a numerical representation of the analog signal detected by the thermocouple, was converted into digital data Mt [°C] using a Type K standard thermoelectric power table specified in the Japanese Industrial Standards. Then, this digital data Mt was interpolated using the linear interpolation shown in the following equation (1). In equation (1), Fn+1 and Fn represent the reference values ​​of the correction data 30, Sn+1 and Sn represent the calibration values ​​of the correction data 30, and n is a value that satisfies the conditions of the following equation (2).

[0060]

number

[0061]

number

[0062] Note that in the above formula (2), a calibration value may be used instead of a reference value. Also, when n satisfying the above formula (2) is 0 (when the digital data Mt is less than the minimum reference value F1), F1 is used as F0, and when n is 0 (when the digital data Mt is greater than the maximum reference value Fn), Fn is used as Fn+1.

[0063] Table 1 shows the reference values ​​(F1, ..., F7) and calibration values ​​(S1, ..., S7) of the prototype measuring instrument, which are the final calibration results and represent the unique data of the probe of the prototype measuring instrument. In the calibration of the prototype measuring instrument, a resistance thermometer using platinum (Pt) was used as the reference measuring instrument, and the temperature of the object to be measured was changed in increments of 50°C in the positive temperature range and in increments of 40°C in the negative temperature range.

[0064] [Table 1]

[0065] Table 2 shows the default data for the reference and calibration values, set to 50°C increments in the positive temperature range and 40°C increments in the negative temperature range, to match the specific data of the prototype measuring instrument.

[0066] [Table 2]

[0067] Figure 8 shows the results of measurements with the unique data shown in Table 1 stored in the RF tag of the prototype measuring instrument's probe (solid line), and the results of measurements without storing the unique data shown in Table 1 in the RF tag of the prototype measuring instrument's probe (dotted line). It should be assumed that during the measurements, there were no situations where the arithmetic unit's reader was unable to acquire the unique data stored in the RF tag.

[0068] In measurements where RF tag-specific data is not stored, the default data shown in Table 2 is used in the linear interpolation of equation (1) above. It can be seen that it is possible to process the output value Dt even when using the default data. As shown by the dotted line in Figure 8, the output value Dt using the default data does not change from the original digital data Mt and can be seen that it contains mechanical error. On the other hand, in measurements where RF tag-specific data is stored, the unique data shown in Table 1 is used in the linear interpolation of equation (1) above. As shown by the solid line in Figure 8, it can be seen that the output value Dt using the unique data is closer to the true value because the mechanical error contained in the digital data Mt is eliminated. Furthermore, even with seven pairs of reference values ​​and calibration values ​​for the unique data, the error in the measurable range was kept to less than 0.1°C. [Explanation of symbols]

[0069] 1 Measuring instrument 10 Arithmetic unit 12. Arithmetic Processing Unit 13 Main memory 14 Auxiliary storage 17 Female connector 20 probe 21 Measuring elements 24 Male Connectors 30 Correction data 31 Unique Data 32 Default Data 33 Leader 34 RF tags Analog signal Mt Digital Data Dt output value

Claims

1. In a measuring instrument calculation device comprising a calculation processing unit, a storage unit, a female connector, and a reader, wherein the male connector of a probe is detachably inserted into the female connector, and the calculation processing unit and the probe are electrically connected, The arithmetic processing unit performs a measurement process to calculate an output value representing the physical quantity to be measured by correcting the digital data obtained by converting the analog signal transmitted from the probe based on data stored at a predetermined memory address in the storage unit. The memory unit has predetermined data stored in advance that does not account for the mechanical error of the probe. Prior to the measurement process being executed, the reader performs a data acquisition process in which, by communicating with the RF tag of the probe connected to the calculation processing unit, unique data stored in the RF tag, in which the mechanical error of the probe is known in advance, is acquired. The calculation device of a measuring instrument is characterized in that, in the measurement process that is executed, if the unique data is acquired in the data acquisition process, the unique data is used as the data, and if the unique data is not acquired, the default data is used as the data.

2. The arithmetic processing unit performs data processing to save the default data to the predetermined memory address before the reader performs the data acquisition process, and when the reader performs the data acquisition process and acquires the unique data, it performs data processing to overwrite and save the unique data to the predetermined memory address, according to claim 1.

3. The arithmetic device for a measuring instrument according to claim 2, wherein the arithmetic processing unit stores the default data at the predetermined memory address and then instructs the reader to execute the data acquisition process.

4. The arithmetic processing unit performs data processing that makes it possible to distinguish whether the default data or the unique data was used as the data in the measurement process, according to any one of claims 1 to 3.

5. The arithmetic device for a measuring instrument according to any one of claims 1 to 4, wherein the female connector is a receptacle housing a plurality of contacts connected to each wire derived from the arithmetic processing unit, the reader has a reader antenna facing the tag antenna built into the RF tag when the male connector of the probe is inserted into the female connector, and the communication method is an electromagnetic induction method.

6. The calculation device for a measuring instrument according to any one of claims 1 to 5, wherein the aforementioned unique data is accumulated in multiple sets of reference values ​​obtained from measurements using a measuring instrument of a different standard than the measuring instrument in question and calibration values ​​obtained from measurements using the measuring instrument in question, the amount of change in the calibration value with respect to the amount of change in the reference value is nonlinear, and the predetermined data is accumulated in multiple sets of reference values ​​and calibration values ​​created such that the difference is zero in any set.

7. A calculating device for a measuring instrument according to any one of claims 1 to 6, wherein the measuring instrument is a thermocouple temperature sensor.

8. The arithmetic device for a measuring instrument according to any one of claims 1 to 7, wherein, at a stage prior to the data acquisition process, the arithmetic processing unit performs data processing to save the default data as the data to the memory address, if the unique data is not acquired by the data processing, the measurement process is performed using the default data, and if the unique data is acquired by the data processing, the arithmetic processing unit performs data processing to save the unique data to the memory address, and the measurement process is performed using the unique data.

9. A measuring instrument comprising: a calculation device for a measuring instrument according to any one of claims 1 to 8; and a probe having the RF tag on which the unique data is stored, which is electrically connected to the calculation device.

10. In a measurement method for a measuring instrument, the male connector of the probe is detachably inserted into the female connector of the computing device, thereby electrically connecting the computing processing unit of the computing device and the probe, After performing a data acquisition step in which the leader of the arithmetic unit communicates with the RF tag of the probe connected to the arithmetic processing unit and acquires unique data stored in the RF tag in which the mechanical error of the probe is known in advance, the arithmetic processing unit performs a measurement step in which it outputs an output value indicating the physical quantity to be measured by correcting the digital data obtained by converting the analog signal transmitted from the probe based on data stored at a predetermined memory address in the storage unit of the arithmetic unit. The measurement method for a measuring instrument is characterized in that, in the measurement step, if the unique data is acquired in the data acquisition step, the unique data is used as the data, and if the unique data cannot be acquired, predetermined data that is pre-stored in the storage unit and in which the mechanical error of the probe is not known is used as the data.

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