JP4167274B2 - Measuring device with electrodes with memory - Google Patents

Description

  The present invention relates to a measuring device such as a pH meter, an ion meter, and an electric conductivity meter provided with a measuring electrode that is detachable from the main body of the device, and in particular, the measuring electrode has a storage means (memory). Information related to electrode characteristics and the like is input to this memory, and the present invention relates to a very convenient measuring apparatus.

  For example, in a measuring device such as a pH meter or ion meter equipped with a measuring electrode that is detachable from the main body of the device, the characteristics of each electrode are calibrated using a standard solution before use, and the calibration data is used as a basis. The measured value is corrected and displayed. In addition, electrodes that require a correction value, such as an electric conductivity cell in an electric conductivity meter, are required to read the correction value displayed on the electrode visually and set this correction value in the main body of the device. Is done.

  Therefore, as described above, in the conventional measuring apparatus, the data or correction value calibrated when using the electrode is stored in the memory in the apparatus main body, so that the electrode is replaced with another electrode. For this new electrode, it is necessary to perform calibration again using the standard solution and to set a new correction value.

  Some measurement devices store several calibration values that can be selected and used, but the user must remember which data belongs to which electrode. That is, the apparatus main body could not automatically identify the electrode.

  In addition, for electrodes that require correction values, such as electrical conductivity cells, the cell constant must be set in the device body as described above, but electrical conductivity cells have electrodes of various shapes depending on the application. Cell constants must be set each time, for example, when replacing them. Therefore, there are cases where accurate measurement cannot be performed due to incorrect settings or forgotten settings. Further, when the measurement result is printed, only the measurement result is printed, and it is impossible to print which electrode is used to obtain the result.

  Therefore, an object of the present invention is to provide a measuring apparatus having an electrode with a memory that can be used properly according to the application, without the need to calibrate or set a correction value every time the electrode is replaced. is there.

  Another object of the present invention is to provide a measuring apparatus including an electrode with a memory capable of managing an electrode such as an electrode calibration history and a use state.

  Another object of the present invention is to provide a measuring device including an electrode with a memory that eliminates setting differences and forgets to set and allows easy electrode replacement.

The above object is achieved by a measuring apparatus having an electrode with a memory according to the present invention. In summary, the present invention relates to a measuring apparatus comprising an apparatus main body and a measurement electrode that is detachable from the apparatus main body, and the measurement electrode is disposed in the measurement electrode or the apparatus main body. A storage means for storing information about the measurement electrode in the cable or connector for connecting the measurement electrode, and a function for reading the information stored in the storage means of the measurement electrode in the apparatus body, provided the ability to write information in the storage means, in the storage means, as the information about the measuring electrode, the electrodes deterioration determination information for at least the measurement electrode, so as to be stored therein using the write function of the apparatus main body The measurement electrode is a pH electrode or an ion electrode, and the electrode deterioration determination information is a reference asymmetric potential or sensitivity of the measurement electrode, and the apparatus body When the asymmetric potential calculated at the time of calibration of the measurement electrode is a predetermined value or more than the reference asymmetric potential stored in the storage means, or the sensitivity calculated at the time of calibration of the measurement electrode is stored in the memory. The measurement device is characterized in that it determines that the measurement electrode has deteriorated when the reference sensitivity stored in the means falls below a predetermined value or more .

According to the present invention,
(1) There is no need to calibrate or set a correction value every time the electrode is replaced, and the electrode for each application can be used properly.
(2) Electrode management such as electrode calibration history and usage status is possible and easy.
(3) Eliminate setting differences and forgetting settings, and easily replace electrodes.
Such effects can be achieved.

  Hereinafter, the measuring device provided with the electrode with a memory according to the present invention will be described in more detail with reference to the drawings. In the following examples, a pH meter mainly including a pH electrode will be described. However, the present invention also includes various other types including an ion electrode, an electric conductivity cell, a resistance temperature sensor electrode, a dissolved oxygen electrode, and the like. The present invention can be applied to other measuring devices.

Example 1
FIG. 1 shows a pH meter 1 which is an embodiment of the measuring apparatus of the present invention. The pH meter 1 as described above has a pH measuring electrode 10 that is provided with a pH sensitive portion 11 such as a glass sensitive film at the tip and is formed into an elongated shape, and processes a signal from the pH measuring electrode 10 for display. The measurement electrode 10 is detachably connected to the apparatus main body 20 by a connector 13 via a cable 12.

  According to the present invention, as shown in FIG. 2, the printed circuit board 14 is disposed adjacent to the end of the measurement electrode 10 opposite to the pH sensitive portion 11, and data required by the electrode is stored therein. It is set as the structure which attaches the memory | storage means 15 for making it do. Alternatively, as shown in FIG. 3, the storage means 15 can be provided on a printed circuit board 14 in a connector 13 attached to the tip of a cable 12 for connecting the measurement electrode 10 to the apparatus main body 20. .

  In this embodiment, an EEPROM (Electrically Erasable Programmable Read-Only Memory) is used as the electrode storage means 15, but the storage means 15 further includes a flash memory, a battery, and the like. RAM with backup, EPROM, and one-time ROM can also be used.

  As described above, in the measuring device 1 such as a pH meter provided with the measurement electrode 10, the characteristics of the electrode are calibrated using a standard solution before use, and the measurement value is calculated and corrected based on the calibration result. Need to be displayed.

  Therefore, for example, in the memory 15 provided in the electrode 10, as the electrode information (data), the model name and the manufacturing number are input at the time of manufacturing the electrode, and the calibration data is written at the time of inspection of the electrode. Further, the information stored in the memory 15 may include electrode usage time data or electrode deterioration data.

  According to the present invention, the apparatus main body 20 has means for reading and storing information stored in the memory 15 of the measurement electrode 10, and new calibration data or the like is stored in the memory 15 of the measurement electrode 10. Means for writing.

  Next, with reference to FIG. 4, the operation | movement aspect of the measuring apparatus of the said structure according to this invention is demonstrated.

  In order to perform measurement with a pH meter, the connector 13 of the measurement electrode 10 is connected to the apparatus main body 20, the power is turned on, and the measurement mode is started. The apparatus main body 20 first reads the model name, serial number, etc. of the electrode 10 from the memory 15 of the connected electrode 10 by the reading / writing means provided in the apparatus main body 20 (step 1). It is determined whether or not X) is the electrode (M) that was previously used (step 2). If it is determined that this electrode (X) is the electrode (M) used previously, the previous data is used as it is (step 3). If it is determined that this electrode (X) is not the electrode (M) used previously, the calibration data is read from the memory 15 of this electrode (X) and stored in the memory of the apparatus body 20 (step 4). ).

  The apparatus body 20 calculates and corrects the pH value based on the read calibration data and the potential obtained from the measurement electrode 10, and displays it as the measured pH value (step 5). In addition, a measuring device equipped with a printer can also perform printing as necessary.

  As described above, according to the present invention, the device main body 20 uses the data individually stored in the connected electrodes 10 to identify the model name, serial number, etc. of the electrodes, and the device main body 20. Rewrite data inside.

  Next, the calibration procedure using the standard solution of the pH measurement electrode performed as necessary will be described with reference to FIG.

  Turn on the power and start the calibration mode. The electrode 10 connected to the apparatus main body 20 is immersed in a standard solution (step 1). As pH standard solutions, oxalate pH standard solution (pH 1.68 / at 25 ° C.), phthalic acid pH standard solution (pH 4.01 / at 25 ° C.), neutral phosphate pH standard solution (pH 6.86 / at 25 ° C.) ), Borate pH standard solution (pH 9.18 / at 25 ° C.).

  Next, when it is determined that the measured potential is stable (step 2), the type of the standard solution used is identified, and the pH value of the standard solution at that time is calculated (step 3). That is, first, an electrode is inserted into a standard solution, the generated potential is read, temperature compensation is calculated, and the standard solution is identified from the value.

  Next, since the standard solution has temperature characteristics and the pH value varies depending on the temperature, the pH value of the standard solution is calculated based on the temperature measured by a temperature sensor provided separately from the electrode 10. Next, the measured potential and the calculated pH value are stored in the memory of the apparatus main body 20 (step 4), and the apparatus main body 20 further writes calibration data in the memory 15 of the measurement electrode 10 by the writing means (step 4). Steps 4, 5).

  Such calibration of the measurement electrode 10 can be performed by connecting the electrode 10 to the apparatus main body 20 as described above, but can also be performed by preparing a dedicated calibrator. In this case, the apparatus body 20 only needs to function as a simple display for displaying the measurement value.

Example 2
In this embodiment, the case where the present invention is applied to an electric conductivity meter and its cell (electrode) will be described.

  Also in this embodiment, as in the case of the first embodiment, a memory means, for example, an EEPROM is provided in the cell itself or in a connector to the apparatus main body. In this memory, the model name and serial number are written at the time of manufacture, and the cell constant is written at the time of inspection.

  Therefore, when this cell is connected to the device body, the device body reads the cell constant from the cell, stores it in the memory of the device body, uses this data to calculate and correct the measured value, and displays it as the measured electrical conductivity. Printing is performed according to

  As described above, in the present embodiment as well, in the same manner as in the first embodiment, the apparatus main body monitors the state of the cell and changes the cell constant when the cell is replaced. When the electric conductivity cell is calibrated using a standard solution, the cell constant can be automatically calculated and this value can be stored in the cell.

  As described above, according to the present invention, since the cell constant can be automatically set, there is no need to forget or make a mistake.

Example 3
A measuring device having an electrode with an expiration date will be described. For example, a pH electrode may need to be calibrated by a metric method, such as when used for transaction proofing, in which case the validity period for the electrode is one year. In such a measuring apparatus, when the electrode is started to be used, the expiration date is written in the memory of the electrode by the writing function of the apparatus body. The device body reads the expiration date stored in the electrode memory each time the electrode is used, compares it with the clock built in the device body, displays on the display that the time limit is approaching, and informs the user. be able to. If the time limit has expired, a warning can be issued to the user or the use can be stopped.

  If necessary, the user can set the calibration expiration date with the standard solution. In other words, the user writes the date and time of calibration of the standard solution to the measurement electrode when the electrode is calibrated using the writing function of the main body of the device, compares the calibration date and time of the electrode with the valid period, and gives warnings and warnings. Message can be displayed at any time.

  It is also possible to store the usage time of the electrodes in a memory. That is, the usage time is obtained by integrating the time during which the electrode is connected to the measuring instrument while the measuring instrument is powered on. According to the present invention, each electrode can be distinguished, so that even if the electrode is replaced, each accumulated time can be determined.

  Furthermore, electrode deterioration determination information can be stored in the electrode memory. That is, each electrode has a theoretical generated potential. Calibration is necessary because there are differences depending on the individual electrodes, but basically no potential is generated that is far from the theory. Therefore, it can be determined that the degradation is, for example, 10% below the theoretical potential.

For example, the pH meter performs two-point calibration and calculates the asymmetry potential and sensitivity. However, when 0 mV or more is ± 30 mV or more with respect to the asymmetry potential, it is abnormal and the sensitivity is 59.16 mV based on 10 % can be determined to be abnormal (deteriorated) when it falls below or more.

  As described above, according to the measuring apparatus of the present invention, the electrodes individually store the expiration date or calibration date, electrode usage time, and electrode deterioration judgment information, so that the management of the electrodes is extremely effective. Achieved.

  Although the above description has been given with reference to a pH meter, the present invention can be similarly applied to an ion meter, an electric conductivity meter, a dissolved oxygen meter, and the like to achieve the same effect.

Example 4
In the case of a measuring device using an ionic selection electrode, when calibration is performed using an ion standard solution, the result is written in the electrode memory, and the calibration date and time is also written together with the calibration data. In the case of an ion electrode, since there are various ion electrodes, the type of ions measured from the read model name can be displayed or printed together with the measurement result. Therefore, several types of ion electrodes can be used without requiring a special switching operation of the apparatus main body. Of course, the calibration deadline can also be managed in the same manner as in the above embodiment based on the data stored in the electrodes.

Example 5
In a measuring device such as a thermistor-type thermometer, a correction resistor is inserted into the thermistor as a measurement electrode or an element having the same characteristics is selected and used in order to increase the accuracy or compatibility of temperature measurement. ing. Therefore, according to the present invention, the storage means is arranged on the thermistor electrode or in the cable or connector, and the characteristic data of the thermistor, for example, the B constant, the nominal resistance value, etc. are written, and this data is read and measured at the time of connection Highly accurate measurement can be performed by calculating from the resistance value.

  The present embodiment can be similarly applied to a measuring apparatus using other resistance type temperature measuring electrodes such as a platinum resistor instead of the thermistor electrode, and the same effect can be achieved.

It is a perspective view which shows the whole structure of the measuring device of this invention. It is a fragmentary broken view of the measurement electrode of a measuring device. It is sectional drawing of the connector part of a measuring device. It is a flowchart explaining the action | operation at the time of a measurement. It is a flowchart explaining the action | operation at the time of calibration.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 10 Measuring electrode 12 Cable 13 Connector 14 Printed circuit board 15 Memory | storage means (memory)
20 Device body

Claims (1)

In a measurement apparatus comprising an apparatus main body and a measurement electrode that is detachable from the apparatus main body,
In the measurement electrode or in a cable or connector for connecting the measurement electrode to the apparatus main body, a storage means for storing information on the measurement electrode is provided,
The apparatus body is provided with a function of reading information stored in the storage means of the measurement electrode, and a function of writing information into the storage means,
In the memory means, as information on the measuring electrode, it has become the electrodes deterioration determination information for at least the measurement electrode, so as to store using a write function of the apparatus main body,
The measurement electrode is a pH electrode or an ion electrode, the electrode deterioration determination information is a reference asymmetry potential or sensitivity of the measurement electrode, and the apparatus body is provided with an asymmetry calculated at the time of calibration of the measurement electrode. When the potential is a predetermined value or more than the reference asymmetric potential stored in the storage means, or the sensitivity calculated at the time of calibration of the measurement electrode is higher than the reference sensitivity stored in the storage means A measuring device characterized by determining that the measurement electrode has deteriorated when the value falls below a value .

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