JP3187757U - electronic balance - Google Patents

Abstract

An electronic balance capable of calibrating a sensitivity coefficient using a weight having a more appropriate mass value is provided.
A plurality of mass values of a sample calculated at the time of past weighing are stored in a weighing history storage unit 32, and a mass value of a weight when a sensitivity coefficient is calibrated is calculated based on the mass value. The determination part 25 determines and the weight value alerting | reporting part 26 alert | reports the mass value of the weight. Thereby, for example, it is possible to specify a mass value range that is frequently weighed during past weighing, and to notify the mass value of the weight determined within the range. In this case, the user simply sets the weight of the reported mass value on the weighing pan 11 and weighs it, and uses the weight within the mass value range that is frequently weighed to determine the sensitivity coefficient. Can be calibrated. Therefore, the sensitivity coefficient can be calibrated using a weight having a more appropriate mass value.
[Selection] Figure 1

Description

  The present invention relates to an electronic balance for weighing an object to be weighed placed on a weighing pan.

  Some electronic balances can measure a weight having a known mass value and store the relationship between the measured value and the actual mass value as a sensitivity coefficient. (For example, refer to Patent Document 1 below). When a sample is weighed with this type of electronic balance, the mass value of the sample can be measured by correcting the measured value of the obtained sample with the sensitivity coefficient. The measured mass value of the sample is displayed as a count value on the display unit.

  However, the sensitivity coefficient may deviate with the use of an electronic balance. In addition, the sensitivity coefficient may not be an appropriate value due to changes in the usage environment (for example, temperature) of the electronic balance. Therefore, in order to accurately measure the mass value of the sample, work for calibrating the sensitivity coefficient is regularly performed.

  FIG. 6 is a diagram for explaining an aspect when a conventional sensitivity coefficient is calibrated. As an example, when the maximum mass value (maximum weighing point) that can be weighed in the electronic balance is 620 g, measurement is first performed using a weight having a mass value (for example, 500 g) close to the maximum weighing point.

  Specifically, the weight value F after correction is obtained by correcting the weight value obtained by weighing the 500 g weight (count value Wref = 50000) with the sensitivity coefficient. If the sensitivity coefficient is an appropriate value, the mass value F of this weight should be 500 g (count value F = 50000). However, assuming that the sensitivity coefficient has shifted, for example, the count value F = 49991. Suppose there was.

  In addition, the weight value Z in the unloaded state after correction is corrected by correcting the measured value obtained by weighing in a state where nothing is placed on the weighing pan (no load state). Get. The mass value Z in the unloaded state should be 0 g (count value Z = 0) if the sensitivity coefficient is an appropriate value. For example, the count value Z = Suppose that it was 1.

In this case, if the mass value of the sample is measured with the sensitivity coefficient shifted, the display value (count value) becomes a value different from the actual mass value, as indicated by a line L101 in FIG. Therefore, in such a case, for example, the sensitivity coefficient can be calibrated by recalculating the sensitivity coefficient K by the following equation.
K = (F−Z) / Wref = (4991-1) /50000=0.998

Thereafter, when the mass value of the sample is measured, the corrected display value WG can be calculated by the following formula using the calibrated sensitivity coefficient K and displayed on the display unit. Thereby, as indicated by a line L102 in FIG. 6, the display value WG can be matched with the actual mass value.
WG = (Weighing value before correction) / K

JP 2012-7970 A

  As described above, the calibration of the conventional sensitivity coefficient has been performed using a weight having a predetermined mass value (500 g in the above example). However, some users may want to calibrate the sensitivity coefficient using a weight within the range of mass values to be frequently measured. Therefore, it is conceivable that the sensitivity coefficient can be calibrated using an arbitrary weight, but when multiple users use a common electronic balance, the range of mass values to be frequently measured is set. Each user does not necessarily know all, and there is a possibility that the sensitivity coefficient cannot be calibrated using a weight of an appropriate mass value.

  This invention is made | formed in view of the said situation, and it aims at providing the electronic balance which can calibrate a sensitivity coefficient using the weight of a more suitable mass value.

  An electronic balance according to the present invention includes a weighing unit for weighing an object to be weighed placed on a weighing pan, and a sample mass value based on a measured value and a sensitivity coefficient of the sample measured by the weighing unit. And a sensitivity coefficient for calibrating the sensitivity coefficient based on the weight value obtained by the weight section by placing a weight having a known weight value on the weighing pan. Calibration unit, weighing history storage unit for storing a plurality of sample mass values calculated by the mass value calculation processing unit at the time of past weighing, and a plurality of mass values stored in the weighing history storage unit A weight value determining unit for determining the mass value of the weight when the sensitivity coefficient is calibrated, and a weight value notifying unit for notifying the mass value of the weight determined by the weight value determining unit. It is characterized by.

  According to such a configuration, a plurality of sample mass values calculated at the time of past weighing are stored in the weighing history storage unit, and the mass value of the weight when the sensitivity coefficient is calibrated based on these mass values. Can be determined. Thereby, for example, it is possible to specify a mass value range that is frequently weighed during past weighing, and to notify the mass value of the weight determined within the range.

  In this case, the user calibrates the sensitivity coefficient using the weight within the range of the mass value that is frequently weighed simply by placing the weight of the reported mass value on the weighing pan and weighing it. can do. Therefore, the sensitivity coefficient can be calibrated using a weight having a more appropriate mass value.

  The electronic balance may further include a confirmation operation unit that is operated to confirm the mass value of the sample calculated by the mass value calculation unit during measurement of the sample. In this case, the weighing history storage unit may store the mass value of the sample determined by the operation of the determination operation unit.

  According to such a configuration, each time the mass value of the sample is confirmed by operating the confirmation operation unit, the confirmed mass value is stored in the weighing history storage unit, and based on those mass values, The mass value of the weight when the sensitivity coefficient is calibrated can be determined. In this case, it is possible to determine the mass value of the weight when the sensitivity coefficient is calibrated based on the mass value determined by the user's intention, and the mass value unintentional to the user is not used. The sensitivity coefficient can be calibrated using a weight of a proper mass value.

  The electronic balance may further include a stability detection unit that detects that the variation of the mass value of the sample calculated by the mass value calculation unit is stabilized within a predetermined range during measurement of the sample. In this case, the measurement history storage unit may store the mass value of the sample when it is detected that the stability detection unit is stable.

  According to such a configuration, every time it is detected that the change in the mass value of the sample is stable, the mass value at that time is stored in the weighing history storage unit, and the sensitivity coefficient is calculated based on the mass value. The mass value of the weight at the time of calibrating can be determined. In this case, since the sensitivity coefficient can be calibrated using a mass weight automatically determined without any special operation by the user, the sensitivity coefficient can be reliably set using a more appropriate mass weight. Can be calibrated.

  The electronic balance may further include a weight value storage unit for storing in advance a mass value for each usable weight. In this case, the weight value determination unit may determine the mass value of the weight when the sensitivity coefficient is calibrated based on the mass value for each weight stored in the weight value storage unit.

  According to such a configuration, when the weight that can be used is different for each user, the mass value of the weight that can be used is stored in the weight value storage unit in advance by storing the mass value for each weight that can be used. Within the range, the mass value of the weight when the sensitivity coefficient is calibrated can be determined. Therefore, the sensitivity coefficient can be reliably calibrated using a weight that can be used by the user.

  The sensitivity coefficient calibration unit includes a weight value obtained by the weighing unit by placing the weight of the mass value determined by the weight value determining unit on the weighing pan, and the weighing unit in a no-load state. The sensitivity coefficient may be calibrated based on the obtained measured value.

  According to such a configuration, it is possible to calibrate the sensitivity coefficient between the weight measurement value of the mass value determined by the weight value determination unit and the measurement value in the no-load state. Thus, the sensitivity coefficient can be calibrated to an appropriate value within the minimum necessary range including the mass value that the user frequently measures, and the mass value of the sample can be accurately measured.

  The sensitivity coefficient calibration unit has a weight value determined by the weight value determination unit and a weight value obtained by the weighing unit by placing the weight value weight on the weighing pan, and the maximum weight that can be used. The sensitivity coefficient may be calibrated based on the measurement value obtained by the measurement unit by placing a mass weight on the weighing pan.

  According to such a configuration, it is possible to calibrate the sensitivity coefficient between the weight value of the weight value determined by the weight value determination unit and the weight value of the weight value of the maximum usable mass value. This makes it possible to accurately measure the mass value of the sample using the sensitivity coefficient calibrated to an appropriate value, even when the measurement is performed beyond the mass value that the user frequently weighs. Can do.

  According to the present invention, the user can calibrate the sensitivity coefficient by using a weight having a more appropriate mass value simply by placing the weight having the reported mass value on the weighing pan and weighing the weight.

It is the block diagram which showed the electrical structure of the electronic balance which concerns on one Embodiment of this invention. It is the flowchart which showed an example of the process by the control part for calibrating a sensitivity coefficient in the electronic balance of FIG. It is a figure for demonstrating the aspect at the time of calibrating a sensitivity coefficient in the electronic balance of FIG. It is the block diagram which showed the electrical structure of the electronic balance which concerns on another embodiment of this invention. It is the flowchart which showed an example of the process by the control part for calibrating a sensitivity coefficient in the electronic balance of FIG. It is a figure for demonstrating the aspect at the time of calibrating the conventional sensitivity coefficient.

  FIG. 1 is a block diagram showing an electrical configuration of an electronic balance according to an embodiment of the present invention. The electronic balance in this embodiment includes an electronic balance equipped with an electromagnetic force balance mechanism, an electronic balance (also referred to as an electronic balance) such as a load cell type, a tuning fork type, and a capacitance type, and a weight load of an object to be weighed. In general, a weighing device that detects an error and outputs an electrical signal is included. In the present embodiment, the electronic balance includes a control unit 2, a storage unit 3, a display unit 4, and an operation unit 5 in addition to the load detection unit 1 that detects the load of an object to be weighed placed on the weighing pan 11. I have.

  The control unit 2 is for controlling the operation of the electronic balance, and includes, for example, a CPU (Central Processing Unit). The control unit 2 functions as a weighing unit 21, a mass value calculation unit 22, a sensitivity coefficient calibration unit 23, an output processing unit 24, a weight value determination unit 25, a weight value notification unit 26, and the like when the CPU executes a program. .

  The storage unit 3 is configured by, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory), and the sensitivity coefficient storage unit 31, the measurement history storage unit 32, the weight value storage unit 33, and the like are allocated to the storage region. . The display part 4 is comprised, for example with the liquid crystal display, and can display various information, such as a measurement result. The operation unit 5 includes, for example, a plurality of operation keys, and the user can give instructions regarding the operation of the electronic balance by operating the operation unit 5.

  The weighing unit 21 measures the object to be weighed placed on the weighing pan 11 based on the detection signal from the load detection unit 1. The measured value obtained at this time is usually a value different from the actual mass value of the object to be weighed, and the mass value calculating unit 22 corrects the measured value using the sensitivity coefficient, whereby the mass value of the object to be weighed is obtained. Can be calculated.

  However, since the sensitivity coefficient may deviate from an appropriate value, it can be periodically calibrated during daily inspection. When the sensitivity coefficient is calibrated, a weight having a known mass value is placed on the weighing pan 11, and the sensitivity coefficient calibration unit 23 determines the sensitivity coefficient based on the weight measurement value obtained by the weighing unit 21. It will be calibrated.

  The sensitivity coefficient calibrated by the sensitivity coefficient calibration unit 23 is stored in the sensitivity coefficient storage unit 31. When the sample is weighed, the mass value calculation unit 22 calculates the sample mass value based on the sample measurement value measured by the measurement unit 21 and the sensitivity coefficient stored in the sensitivity coefficient storage unit 31. calculate.

  The output processing unit 24 performs processing for outputting the mass value calculated by the mass value calculating unit 22. For example, the output processing unit 24 can cause the display unit 4 to display the mass value by outputting the mass value calculated by the mass value calculating unit 22 to the display unit 4. When the print instruction unit 51 included in the operation unit 5 is operated, the output processing unit 24 outputs the mass value to the printer 6 connected to the electronic balance, thereby measuring the mass value. As a result, it can be printed.

  In the present embodiment, when the print instruction unit 51 is operated during the measurement of the sample, the sample mass value determined by the operation is stored in the measurement history storage unit 32. The weighing history storage unit 32 stores a mass value each time the print instruction unit 51 is operated, whereby a plurality of mass values are stored as past weighing history. The latest predetermined number of mass values may be stored in the weighing history storage unit 32 and may be deleted sequentially from the oldest data.

  At this time, the print instruction unit 51 constitutes a confirmation operation unit operated to confirm the mass value of the sample calculated by the mass value calculation unit 22. However, the confirmation operation unit is not limited to the print instruction unit 51, and the mass value of the sample calculated by the mass value calculation unit 22 is confirmed by the operation of another confirmation operation unit such as a confirmation key. May be stored in the weighing history storage unit 32.

  The weight value determining unit 25 determines the mass value (weight value) of the weight when the sensitivity coefficient is calibrated. In the present embodiment, the weight value determining unit 25 determines the weight value based on a plurality of mass values stored in the weighing history storage unit 32. The weight value determined by the weight value determining unit 25 is notified to the user by causing the weight value notifying unit 26 to display on the display unit 4 via the output processing unit 24.

  Specifically, from a plurality of mass values stored in the weighing history storage unit 32, a range of mass values frequently measured during past weighing is specified, and the mass of the weight determined within the range is determined. The value is reported. Various methods can be used as a method for specifying the mass value range frequently measured at the time of past measurement. For example, the mass value range is divided into a plurality of ranges within the measurable range. A method of counting the number of times of measurement in each range by classifying the mass values stored in the history storage unit 32 into each range is conceivable.

  In this case, by specifying a range in which the number of times of measurement is large, a weight value corresponding to the range can be determined as a weight value when the sensitivity coefficient is calibrated. One or a plurality of weight values may be determined. For example, when a predetermined number of ranges are specified in order from the range in which the number of times of measurement is large, a plurality of weight values corresponding to each range are determined as weight values when the sensitivity coefficient is calibrated. It will be.

  In the present embodiment, the user simply puts the weight of the notified mass value (weight value) on the weighing pan 11 and weighs the weight within the mass value range that is frequently weighed. Can be used to calibrate the sensitivity factor. Therefore, the sensitivity coefficient can be calibrated using a weight having a more appropriate mass value.

  In particular, in this embodiment, every time the mass value of the sample is determined by operating the print instruction unit 51, the determined mass value is stored in the weighing history storage unit 32, and based on those mass values. The mass value of the weight when the sensitivity coefficient is calibrated can be determined. In this case, it is possible to determine the mass value of the weight when the sensitivity coefficient is calibrated based on the mass value determined by the user's intention, and the mass value unintentional to the user is not used. The sensitivity coefficient can be calibrated using a weight of a proper mass value.

  In the present embodiment, the weight value determination unit 25 can determine the mass value of the weight when the sensitivity coefficient is calibrated based on the mass value for each weight stored in the weight value storage unit 33. It has become. In the weight value storage unit 33, for example, when the user operates the operation unit 5, the mass value for each usable weight can be stored in advance.

  Thereby, when the useable weight differs for every user, the mass value for every useable weight is stored in the weight value storage unit 33 in advance, and within the range of the mass value of the useable weight. The mass value of the weight when the sensitivity coefficient is calibrated can be determined. Therefore, the sensitivity coefficient can be reliably calibrated using a weight that can be used by the user.

  FIG. 2 is a flowchart showing an example of processing by the control unit 2 for calibrating the sensitivity coefficient in the electronic balance of FIG. When the sample is weighed using the electronic balance according to the present embodiment, the weight value of the weighed sample is measured each time the print instruction unit 51 is operated (Yes in step S101). Is stored in the weighing history storage unit 32 (step S102).

  When the sensitivity coefficient is periodically calibrated in the daily inspection (Yes in step S103), the weight of the weight used when the sensitivity coefficient is calibrated is based on the plurality of mass values stored in the weighing history storage unit 32. The mass value is determined (step S104), and the mass value of the weight is displayed on the display unit 4 to notify the user (step S105).

  Thereafter, the user places a weight of the notified mass value on the weighing pan 11 so that a process for calibrating the sensitivity coefficient based on the weight value of the weight is performed (step S106). When the mass values of a plurality of weights are notified, the user calibrates the sensitivity coefficient based on the measurement values of the respective weights by sequentially placing the weights corresponding to the respective mass values on the weighing pan 11. can do.

  FIG. 3 is a diagram for explaining an aspect when the sensitivity coefficient is calibrated in the electronic balance of FIG. 1. As an example, when the maximum mass value (maximum weighing point) that can be weighed in the electronic balance is 620 g, measurement is first performed using a weight having a mass value (for example, 500 g) close to the maximum weighing point.

  Specifically, the weight value F1 of the weight after the correction is obtained by correcting the weight value obtained by weighing the 500 g weight (count value Wref1 = 50000) with the sensitivity coefficient. If the sensitivity coefficient is an appropriate value, the mass value F1 of the weight should be 500 g (count value F1 = 50000). However, assuming that the sensitivity coefficient has shifted, for example, the count value F1 = 49991. Suppose there was.

  In the present embodiment, the mass value of the weight when the sensitivity coefficient is calibrated is determined based on the plurality of mass values stored in the weighing history storage unit 32, and the mass value of the weight is notified to the user. Thus, weighing is performed using the weight of the notified mass value. The mass value of the weight notified at this time is a mass value in the range R specified as the range of mass values frequently measured at the time of past measurement.

  For example, when the reported mass value of the weight is 200 g, the weight value obtained by weighing the weight of 200 g (count value Wref2 = 20000) is corrected with the sensitivity coefficient, and the corrected weight value is obtained. The mass value F2 of the weight is obtained. The mass value F2 of the weight should be 200 g (count value F2 = 20000) if the sensitivity coefficient is an appropriate value. However, assuming that the sensitivity coefficient is deviated, for example, the count value F2 = 19991. Suppose there was.

  Furthermore, the weight value Z in the unloaded state after correction is corrected by correcting the measured value obtained by weighing in a state in which nothing is placed on the weighing pan (no load state) with the sensitivity coefficient. Get. The mass value Z in the unloaded state should be 0 g (count value Z = 0) if the sensitivity coefficient is an appropriate value. For example, the count value Z = Suppose that it was 1.

  In this case, if the mass value of the sample is measured with the sensitivity coefficient shifted, the display value (count value) becomes a value different from the actual mass value, as indicated by a line L1 in FIG. Therefore, in such a case, the sensitivity coefficients K1 and K2 are recalculated in the section R1 of the weight value from 200 g to 500 g and the section R2 of the weight value from the no-load state to 200 g, respectively. Coefficients can be calibrated.

For the section R2, the sensitivity coefficient K2 can be calibrated by the following equation, for example.
K2 = (F2-Z) / Wref2 = (19991-1) /20000=0.9995

Thereafter, when measuring the mass value of the sample in the section R2, the corrected display value WG can be calculated by the following formula using the calibrated sensitivity coefficient K2 and displayed on the display unit 4. . Thereby, as indicated by a line L2 in FIG. 3, the display value WG can be matched with the actual mass value in the section R2.
WG = (Weighing value before correction) / K2

For the section R1, for example, the sensitivity coefficient K1 can be calibrated by the following equation.
K1 = (F1-F2) / (Wref1-Wref2)
= (4999-119991) / (50000-20000) = 1.0000

Thereafter, when measuring the mass value of the sample in the section R1, the corrected display value WG can be calculated by the following formula using the calibrated sensitivity coefficient K1 and displayed on the display unit 4. . Thereby, as indicated by a line L2 in FIG. 3, the display value WG can be matched with the actual mass value in the section R1.
WG = (Weighing value before correction) / K1 + (Wref2-F2)

  In addition, when there are a plurality of ranges R that are specified as mass value ranges that are frequently weighed at the time of past weighing, the mass values of a plurality of weights are notified, and weighing is performed using the weights of the respective mass values. Will be done. In this case, there are three or more weight value sections, and the sensitivity coefficient is calibrated for each section.

  Thus, in the present embodiment, the sensitivity coefficient K2 between the measured value of the weight of the mass value determined by the weight value determining unit 25 (200 g in the above example) and the measured value in the no-load state is calibrated. Can do. Thereby, the sensitivity coefficient K2 can be calibrated to an appropriate value within the minimum necessary range including the mass value that the user frequently measures, and the mass value of the sample can be measured with high accuracy.

  In the present embodiment, the weight value of the weight value (200 g in the above example) determined by the weight value determining unit 25 and the weight value of the maximum usable weight value (500 g in the above example) Can be calibrated. Thereby, even when the measurement is performed exceeding the mass value that the user frequently measures, the mass value of the sample is accurately measured using the sensitivity coefficient K1 calibrated to an appropriate value. be able to.

  FIG. 4 is a block diagram showing an electrical configuration of an electronic balance according to another embodiment of the present invention. In this electronic balance, the control unit 2 functions as the stability detection unit 27, and the mass value of the sample is stored in the weighing history storage unit 32 based on the detection result by the stability detection unit 27. Except for this point, the other configuration is the same as that of the above-described embodiment. Therefore, the same reference numerals are given to the same configuration, and detailed description is omitted.

  The stability detection unit 27 is for detecting that the fluctuation of the mass value of the sample calculated by the mass value calculation unit 22 is stabilized within a predetermined range during the measurement of the sample. That is, if the fluctuation range of the mass value of the sample within a certain time does not exceed a predetermined threshold value, the stability detection unit 27 detects that the sample is stable, and the mass value at that time is stored in the weighing history storage unit 32 by the output processing unit 24. It has come to be remembered.

  As a result, the weighing history storage unit 32 stores mass values each time it is detected by the stability detection unit 27 that the sample is being weighed, and a plurality of mass values are stored as past weighing history. It will be. The latest predetermined number of mass values may be stored in the weighing history storage unit 32 and may be deleted sequentially from the oldest data.

  FIG. 5 is a flowchart showing an example of processing by the control unit 2 for calibrating the sensitivity coefficient in the electronic balance of FIG. When the sample is weighed using the electronic balance according to the present embodiment, the sample is weighed every time the stability detector 27 detects that the change in the mass value of the sample is stable (Yes in step S201). The mass value of the sample is stored in the weighing history storage unit 32 (step S202).

  When the sensitivity coefficient is periodically calibrated in the daily inspection (Yes in step S203), the weight of the weight used when the sensitivity coefficient is calibrated is based on the plurality of mass values stored in the weighing history storage unit 32. The mass value is determined (step S204), and the mass value of the weight is displayed on the display unit 4 to notify the user (step S205).

  Thereafter, the user places a weight of the notified mass value on the weighing pan 11 to perform a process for calibrating the sensitivity coefficient based on the measured value of the weight (step S206). When the mass values of a plurality of weights are notified, the user calibrates the sensitivity coefficient based on the measurement values of the respective weights by sequentially placing the weights corresponding to the respective mass values on the weighing pan 11. can do.

  In this embodiment, every time it is detected that the change in the mass value of the sample is stable, the mass value at that time is stored in the weighing history storage unit 32, and the sensitivity coefficient is calibrated based on those mass values. The mass value of the weight at the time can be determined. In this case, since the sensitivity coefficient can be calibrated using a mass weight automatically determined without any special operation by the user, the sensitivity coefficient can be reliably set using a more appropriate mass weight. Can be calibrated.

  In the above embodiment, the case where the user calibrates the sensitivity coefficient by placing the weight of the mass value (weight value) displayed on the display unit 4 on the weighing pan 11 and measuring it has been described. However, the user does not need to follow the weight value displayed on the display unit 4, and by placing a weight having a mass value different from the weight value displayed on the display unit 4 on the weighing pan 11 and weighing it, The sensitivity coefficient may be calibrated.

  Further, when notifying the user of the weight value determined by the weight value determining unit 25, the weight value is not limited to the configuration in which the weight value is displayed on the display unit 4, but may be displayed to the user by other modes such as voice, for example. The structure which alert | reports may be sufficient.

DESCRIPTION OF SYMBOLS 1 Load detection part 2 Control part 3 Memory | storage part 4 Display part 5 Operation part 6 Printer 11 Weighing pan 21 Weighing part 22 Mass value calculation part 23 Sensitivity coefficient calibration part 24 Output processing part 25 Weight value determination part 26 Weight value notification part 27 Stability Detection unit 31 Sensitivity coefficient storage unit 32 Weighing history storage unit 33 Weight value storage unit 51 Print instruction unit

Claims (6)

A weighing unit for weighing an object to be weighed placed on a weighing pan;
A mass value calculation unit for calculating a mass value of the sample based on the measurement value and the sensitivity coefficient of the sample measured by the measurement unit;
A sensitivity coefficient calibration unit that calibrates the sensitivity coefficient based on a weight value obtained by the weight unit by placing a weight having a known mass value on the weighing pan; and
A weighing history storage unit for storing a plurality of mass values of the sample calculated by the mass value calculation processing unit at the time of past weighing;
Based on a plurality of mass values stored in the weighing history storage unit, a weight value determining unit that determines a mass value of a weight when the sensitivity coefficient is calibrated,
An electronic balance comprising: a weight value notifying unit for notifying a mass value of a weight determined by the weight value determining unit. Further comprising a confirming operation unit that is operated to confirm the mass value of the sample calculated by the mass value calculating unit during the weighing of the sample,
The electronic balance according to claim 1, wherein the weighing history storage unit stores a mass value of the sample determined by the operation of the determination operation unit. A stability detector for detecting that the variation of the mass value of the sample calculated by the mass value calculator is stabilized within a predetermined range during the measurement of the sample;
The electronic balance according to claim 1, wherein the weighing history storage unit stores a mass value of the sample when the stability detection unit detects that the measurement is stable. A weight value storage unit for storing in advance a mass value for each usable weight,
The weight value determination unit determines a mass value of a weight when the sensitivity coefficient is calibrated based on a mass value for each weight stored in the weight value storage unit. 4. The electronic balance according to any one of 3.   The sensitivity coefficient calibration unit includes a weight value obtained by the weighing unit by placing the weight of the mass value determined by the weight value determining unit on the weighing pan, and the weighing unit in a no-load state. The electronic balance according to any one of claims 1 to 4, wherein the sensitivity coefficient is calibrated based on the obtained measured value.   The sensitivity coefficient calibration unit has a weight value determined by the weight value determination unit and a weight value obtained by the weighing unit by placing the weight value weight on the weighing pan, and the maximum weight that can be used. 6. The sensitivity coefficient is calibrated based on a measured value obtained by the measuring unit by placing a mass weight on the weighing pan. Electronic balance.

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