JP5734500B2 - Weighing device - Google Patents

Description

  The present invention relates to a weighing device including a mass meter such as an electronic balance, and more particularly, to a weighing device including a mass meter with high weighing accuracy such as an analytical balance or a micro electronic balance as a constituent element.

  For example, in a weighing apparatus in which a mass meter such as an electromagnetic balance type electronic balance is one of the components and another device such as a PC or a printer for outputting a measurement result is connected to the electronic balance, the temperature / Changes in environmental conditions such as humidity, atmospheric pressure, and vibration affect measurement sensitivity, zero point (measured value when no load is applied), and span value (difference between measured value and zero point when a load with a known mass is measured) It is known that it becomes a factor that hinders high-precision weighing. In particular, in an analytical electronic balance with a measurement value reading accuracy (minimum display) of 0.1 mg or less, and an ultra-high precision micro electronic balance with 1 μg or less, the measurement error caused by changes in the installation environment is the measurement result (measurement value). ) Is very significant.

  Therefore, conventional weighing devices record (monitor) environmental factors (temperature, humidity, atmospheric pressure, vibration, etc.) that affect weighing in order to reduce the error due to changes in the installation environment and bring the measured value closer to the true value. Then, use the environmental measurement data obtained from it as a correction value at the time of calibration (Patent Document 1), evaluate whether the recorded environmental measurement data is within an allowable value for providing the basic performance of the weighing device, Some devices have a function of prompting the user to proofread by displaying the fact when the allowable value is exceeded (Patent Document 2).

JP 62-280624 A (first page, claims) JP 2007-139768 (paragraphs [0046], [0049] to [0053], FIGS. 2 to 5)

  However, in the conventional weighing device described above, there have been many reports from users that the basic performance guaranteed by the weighing device does not come out even when calibration is completed.

  This may be due to changes in the surrounding environment of the device, such as sudden temperature changes due to the operation of air conditioners, changes in atmospheric pressure and humidity due to the passage of low atmospheric pressure, occurrence of earthquakes at remote locations, etc. No matter how much calibration is performed with a drastic change, the basic performance will not be demonstrated unless the changes in the surrounding environment settle down. Although conventional weighing devices record (monitor) environmental changes in these surrounding environments (installation environments), they only disclose (display) the analysis results obtained by monitoring, The change over time) was never disclosed to the user. In addition, the user cannot know how the environmental change affects the measurement result (measurement value) and how the environmental change correlates with the measurement value.

  For this reason, if the basic performance does not come out even after the calibration is completed (the calibration is repeated many times), whether the cause is a performance failure due to the installation environment or the performance of the weighing device itself However, there was a problem in that it was possible to continue weighing or to be able to trust the measured value, and at the same time, it caused a distrust in the mass meter itself.

  The first aspect of the present invention is a problem caused by the installation environment in which the performance of the apparatus is poor by providing the means by which the user can recognize how the installation environment of the weighing apparatus affects the weighing. This is to provide a user-friendly weighing device that can be grasped by the user himself / herself, reduce anxiety during use, and can be used convinced including error factors due to the environment. The provision of a weighing device that can improve the weighing accuracy from a new viewpoint (cutting point) of improving the installation environment.

  In order to achieve the above object, in the weighing device according to the present invention, a load measuring mechanism for detecting weighing data, an environment measuring means for detecting a physical quantity of an environment in which the load measuring mechanism is installed, and the load measuring mechanism A storage means for storing the measurement data detected in step 1 and the environmental measurement data detected by the environmental measurement means, and an arithmetic processing unit for performing arithmetic processing using the measurement data and the environmental measurement data stored in the storage means; , And the arithmetic processing unit records the time-dependent variations of the measurement data and the environmental measurement data in correlation with each other, and visually recognizes the time-dependent variations via a display unit.

  The arithmetic processing unit is configured to record and display a time-dependent change in each of the zero point, which is a measurement value at no load, and the environmental measurement data as the measurement data.

  (Action) Weighing data used to calculate the measurement result (measurement value) of the load mass that is the object to be weighed (corresponding to changes in the environment (temperature, humidity, pressure, vibration, etc.) where the load measurement mechanism is placed ( It is known that the zero point, which is the weighing data at no load, and the weighing, which is the weighing data at the time of loading, fluctuate. For example, a change in temperature causes a sensitivity drift, and a change in mass moment due to a change in humidity and a change in buoyancy due to a change in atmospheric pressure cause a zero point drift.

  Therefore, the environmental measurement data and weighing data around the device are recorded (monitored) at the same time, and the two are correlated to each other, and the changes over time of the environmental measurement data and the weighing data (simultaneous monitoring) are displayed via the display unit. By constructing it so that it can be visually recognized (visually displayed), the correlation between environmental changes and weighing data, which has not been apparent in the past, is disclosed visually. It can be easily recognized that this is due to environmental changes.

  Furthermore, from the simultaneous recording of environmental measurement data and weighing data, the coefficient of change for each numerical value is obtained and a correlation analysis is performed to obtain a coefficient that can determine the correlation between environmental changes and weighing data. By providing a means for determining and evaluating the degree of influence of the parameter and presenting the evaluation result to the user, the user estimates how much the temperature management is improved, for example, how much the measurement data can enter the target management width. Yes, you can move on to improve the environment yourself. Alternatively, by estimating and presenting the minimum display of the measurement value that can be determined in the current environment from the influence determination means, the user can be informed of the maximum performance that can be obtained in the current environment. It is possible to judge whether or not the measurement can be continued on the spot.

  Alternatively, the arithmetic processing unit may calculate a span value that is a difference between a measured value when a load having a known mass is measured as the measured data and a zero point that is a measured value when there is no load, and the environmental measurement data. It was configured to record and display changes over time.

  (Action) Since the weighing data (zero point, weighing) fluctuates due to the environmental change, the correlation between the environmental change and the weighing data can be recognized by recording and correlating them simultaneously. In addition, the mass is known. By recording the variation over time of the span value, which is the difference between the weighing data when the load is weighed and the weighing data when there is no load (zero point), how much the above-mentioned difference is weighed and the known mass Since it is possible to know whether the measurement is stably performed, it is possible to know how the environmental change correlates with the reliability of the weighing device by displaying the fluctuation of the span value together.

  In the weighing apparatus, the arithmetic processing unit is configured to calculate a standard deviation of the span value obtained by repeatedly measuring a load whose mass is known repeatedly, and to record and display the recorded data.

  (Operation) By recording changes over time in the standard deviation of the span value obtained by repeatedly measuring a load with a known mass repeatedly, no matter how many times the same mass is weighed, the span value can be reliably reproduced. Since it is possible to know whether there is the ability to show the same measurement value, how the change in the environment correlates with the reliability of the weighing device by correlating the fluctuation of the standard deviation of the span value together. I understand.

  In the weighing device, the arithmetic processing unit is configured to repeatedly measure the zero point or the weighing to obtain a standard deviation, and record and display the recorded data.

  (Operation) By recording the time variation of the measurement data zero point and the standard deviation of the weighing, it is possible to know how reliably the weighing data is reproduced. By displaying the fluctuations in correlation, it can be seen how the environmental changes correlate with the reliability of the weighing device.

  The measuring device may be configured such that the temporal change is displayed on the display unit as a time-dependent change graph expressed with respect to a time axis.

  (Operation) The time-dependent fluctuation of each numerical value is displayed as a time-series graph on the same time axis, so that the correlation (correspondence) between environmental changes and measurement data, span values, and standard deviations can be easily understood by the user. Disclosed.

  In the weighing device, the environment measuring means is provided in a mass meter having the load measuring mechanism.

  (Operation) The environment measuring means is unitized by being provided in the mass meter which is one of the components of the weighing device.

  According to the present invention, the user can immediately recognize the relationship between the performance failure of the apparatus and the environmental change by visually recognizing (visually displaying) the temporal variation of the environmental measurement data and the weighing data in a correlated manner. As a result, the user's confidence in the weighing device increases. In addition, the basic performance (accuracy) presented by the device is guaranteed by having the user prepare the surrounding environment.

  In addition, the time-dependent fluctuation of the span value that shows how constant the difference between the measurement data when a known load is measured and the measurement data at no load (the measurement is stable) is correlated with the environmental change. Recording makes it easier to understand the correlation between poor performance of the device and changes in the surrounding environment.

  Further, by recording the temporal variation of the standard deviation indicating repeatability in correlation with the environmental change, it becomes easier to understand the correlation between the performance failure of the apparatus and the ambient environment change.

  In addition, the correlation (correspondence) between the environmental change and the measurement data, the span value, and the standard deviation is disclosed in a form that is easier for the user to understand.

  In addition, the unitization saves space and improves the usability of the weighing device.

1 is a block diagram of a weighing device according to a first embodiment of the present invention. The flowchart figure of the environmental evaluation mode which concerns on a 1st Example. Correlation monitoring diagram of environmental measurement data and zero point obtained in the same mode. Correlation monitoring diagram of environmental measurement data and span value obtained in the same mode. Correlation monitoring chart of temperature change and span value obtained in the same mode. Correlation monitoring diagram of environmental measurement data and standard deviation of span values obtained in the same mode. The flowchart figure of the environmental evaluation mode which concerns on a 2nd Example.

  A first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram of a weighing device according to the first embodiment. The illustrated weighing device 100 includes an electronic balance 1 which is a mass meter, a data logger 20 for storing data measured by the electronic balance 1, and an external PC 30 for analyzing measurement data.

  The electronic balance 1 is an electromagnetic balance type micro electronic balance, and has a measurement value reading accuracy (minimum display) of 1 μg (0.001 mg) as a measurement result of a load mass as an object to be weighed.

  In the electronic balance 1, a load measuring mechanism 2 having a load transmission mechanism, an electromagnetic part, etc., a built-in weight adding and removing mechanism 6 for adding and removing a built-in weight 5 having a known mass to the load measuring mechanism 2, and a built-in weight adding and removing mechanism 6 are operated. The motor 7 to be driven and the motor driving circuit 8 for controlling the driving of the motor 7 are provided, and the built-in weight 5 is configured to be automatically raised and lowered. The weighing data detected from the load measuring mechanism 2 is A / D converted from an analog signal to a digital signal by the internal CPU 3, sampled by the data sampling means, and then stored in the data logger 20 (storage means).

  Further, the electronic balance 1 incorporates an environmental sensor 10 (environment measuring means) that detects a change in physical quantity of the environment in which the electronic balance 1 is installed over time. The environmental sensor 10 includes a temperature sensor 11, a humidity sensor 12, and an atmospheric pressure sensor 13. Environmental measurement data (temperature, humidity, and atmospheric pressure) detected over time by the environmental sensor 10 is sampled in the same manner as the measurement data, and then stored in the data logger 20. Although the environmental sensor 10 may be an external device, the electronic balance 1 is a space-saving and easy-to-use electronic balance 1 by being unitized in the electronic balance 1. Further, the electronic balance 1 is provided with a display unit 4 such as a measurement value similar to the conventional display for displaying a measurement value of mass and various setting contents.

  Reference numeral 32 denotes an external CPU (arithmetic processing unit) provided in the external PC 30 and includes an intermediate processing unit and various memory mechanisms. The external CPU 32 obtains a weight measurement value from a variety of programs similar to the conventional one, specifically, a difference between a weighing value that is weighing data when loaded and a zero point that is weighing data when there is no load, The span value (difference between the measurement data and the zero point when measuring a load with a known mass) or the span value obtained by measuring the span value multiple times from the measurement data obtained by the automatic lifting / lowering of the internal weight 5 A program for calculating the standard deviation or the standard deviation of the weighing data obtained by repeatedly measuring the zero point and the weighing several times is stored.

  In addition to the above, the external CPU 32 continuously or temporally changes the measurement data (zero point / weighing) stored in the data logger 20 and the environmental measurement data (temperature, humidity, atmospheric pressure) over time. Intermittent recording, that is, monitoring (acquisition of data over a long period of time), and environmental evaluation that correlates each temporal change with respect to the same time axis are performed. Further, in such environmental evaluation, in addition to the above-described temporal variation, the temporal variation of the calculated span value and / or standard deviation is also correlated. Then, a command is issued so that the correlation of each temporal change is visually displayed via the monitor 31 (display unit) of the external PC 30. Specifically, changes over time in environmental measurement data and changes over time in measurement data or span values or standard deviations of span values are displayed as a time-dependent change graph (correlation monitoring diagram) represented on the same time axis. The command is issued.

  Then, on the monitor 31 of the external PC 30, the above-described correlation monitoring diagram is displayed in real time or in a time width requested by the user in accordance with a command from the external CPU 32 (FIGS. 3, 4, 5, and 6).

  Next, the operation of the above-described environment evaluation mode will be described based on the flowchart of the environment evaluation mode according to the first embodiment shown in FIG.

  When the environmental evaluation mode is entered, first, in step S1, environmental measurement data detected by the environmental sensor 10, that is, measurement data of temperature, humidity, and atmospheric pressure is sampled. The environmental elements to be sampled can be arbitrarily selected according to needs. The sampling data of each environmental element is continuously taken for several hours to several days in step S4 and recorded in the data logger 20. The sampling time can be arbitrarily set according to the needs.

  Simultaneously with step S1, in step S2, the built-in weight 5 is automatically raised and lowered by the load measuring mechanism 2 in a cycle of once per minute, for example, and in step S3, the weight of the built-in weight 5 and the zero point data are measured. (Weighing data) is sampled and recorded in the data logger 20 in the same manner as the environmental measurement data in step S4.

  In step S5, the environmental measurement data and the measurement data recorded in the data logger 20 are read out to the external CPU 32 and monitored in a manner in which both time axes are correlated and correlated.

  At the same time, in step S6, the span value of the internal weight 5 is calculated from the sampled measurement data, and the standard deviation for the true value of the internal weight 5 is calculated from the plurality of span value data. In step S7, the time-dependent fluctuation of the span value is also correlated and monitored with the time axis unified, and the time deviation of the span value standard deviation is also unified at the calculated timing. Correlation monitoring.

  Then, in step S8, as shown in FIGS. 3 to 6, when such temporal variation is output and displayed on the monitor 31 as a correlation monitoring diagram with time on the horizontal axis and numerical values on the vertical axis, End.

  FIG. 3 is a correlation monitoring diagram of environmental measurement data and zero point obtained in the environmental evaluation mode, where environmental measurement data (temperature, humidity, pressure) changes over time and measurement data (zero point) changes over time. It is a time-dependent change graph which shows a mode that it monitored simultaneously. The horizontal axis represents time [day: time], the upper vertical axis represents temperature [° C.], humidity [%], and atmospheric pressure [hPa], and the lower vertical axis represents zero point [g].

  From the monitoring chart of the environmental measurement data (the upper part of FIG. 3), it can be seen that there is a sudden drop in atmospheric pressure and a corresponding increase in humidity around 17:00 on December 3rd. And if you look at the zero point monitoring chart (bottom of Fig. 3), you can see that it is swinging negatively around 17:00 on December 3rd. This detailed reason is due to the fact that the buoyancy applied to the internal weight 5 decreased due to fluctuations in atmospheric pressure and the zero point became heavier, and that the mass moment changed due to an increase in humidity and the balance around the fulcrum of the balance was lost. It is.

  However, as shown in FIG. 3, since the fluctuation of each numerical value is displayed as a time-series graph, the correlation (correspondence) between the environmental change and the measurement data fluctuation is disclosed in a form that is easy to understand by the user. Even if the reason for this is not understood, it can be seen at a glance from FIG. 3 that the sudden fluctuation of the zero point is caused by a decrease in atmospheric pressure and / or an increase in humidity. In other words, the time-dependent fluctuation of the environmental measurement data around the electronic balance 1 and the time-dependent fluctuation of the measurement data are correlated and monitored, and the time-dependent fluctuation is displayed via the monitor 31. Since the correlation between the environmental measurement data and the weighing data that was not present is visually disclosed, the user can easily recognize that the performance failure of the electronic balance 1 is due to a change in the surrounding environment.

  Next, FIG. 4 is a correlation monitoring diagram of the environmental measurement data and the span value obtained in the same mode, in which the lower stage in FIG. 3 is the span value. Since the span value is the difference between the weighing data when a load having a known mass is measured and the zero point, the span value represents the difference between the weight of the built-in weight 5 and the zero point. Then, looking at the monitoring chart of the span value (the lower part of FIG. 4), it is possible to confirm data disturbance around 17:00 on December 3. The reason for this is due to a change in buoyancy caused by a decrease in atmospheric pressure as described above.

  FIG. 5 is a correlation monitoring diagram of temperature change and span value obtained in the same mode. Referring to FIG. 5, it can be confirmed that immediately after the power supply to the electronic balance 1 is turned on, the span value largely fluctuates as the internal temperature of the balance increases. This reason is due to the power-on drift of the mass meter that is usually said.

  However, since the correlation between the two has been disclosed as a time-series graph in an easy-to-understand form for the user, the user can see that the fluctuation of the span value is caused by a decrease in atmospheric pressure and / or an increase in humidity as seen in FIG. From FIG. 5, it can be seen at a glance that the span value fluctuates due to a temperature change until a predetermined time elapses after the power is turned on.

  Next, FIG. 6 is a correlation monitoring diagram of the environmental measurement data and the standard deviation of the span value obtained in the same mode, and the lower stage in FIG. 3 is a graph in which the standard deviation of the span value is obtained. The standard deviation in the present embodiment is indicated by the standard deviation of the span value calculated by repeatedly measuring the built-in weight 5 having a known mass 10 times. And when the monitoring chart of the standard deviation showing the repeatability (the lower part of FIG. 6) is seen, the standard deviation (error) is about 2.5 μg between December 4 and December 8, and is stable. You can see that the weighing is done. That is, the electronic balance 1 guarantees a weighing accuracy of 2.5 μg if there is no large environmental change (this is the basic performance guaranteed by the apparatus). However, it can be seen that a maximum error of 9.0 μg occurs around 17:00 on December 3 when the low pressure passed. This is due to the fluctuation of the span value due to the fluctuation of the atmospheric pressure. However, since the correlation between the two has been disclosed in an easy-to-understand form as a time-series graph, the user generally sees that the standard deviation (error) indicating reliability is large when the atmospheric pressure decreases and It can be seen at a glance that it is caused by an increase in humidity.

  Here, the user can recognize the correlation between the temporal variation of the environmental measurement data and the temporal variation of the measurement data according to FIG. 3, but in addition to this, as shown in FIGS. Since the time-dependent variation of the standard deviation indicating repeatability is also correlated and displayed, it becomes easy to understand how the environmental change correlates with the reliability of the electronic balance 1. For example, if the true value of the mass is 200.0 g and the zero point value is 0.0 g and the weighing is 200.0 g, the span value is 200.0 g. Next, if the zero point value is 0.1 g and the weighing is 200.1 g, the span value is 200.0 g. Therefore, if the span value does not vary even if the zero point varies, it can be said that the performance as a mass meter is sufficiently guaranteed. However, if the value of the zero point is 0.1 g and the weight is 200.5 g, the span value is 200.4 g, which indicates that a performance failure has occurred.

  That is, how stably the known mass is weighed (how much the difference between the weighed weight when a known load is weighed and the zero point when no load is weighed) is measured over time. You can know by monitoring the changes.

  In addition, by monitoring changes over time in the standard deviation of the span value, it is possible to know how reliably the span value is reproduced and how many times the same mass is weighed to show the same measured value. .

  Then, by correlating the span value and the standard deviation of the span value with the environmental change, the correlation between the change in the surrounding environment of the electronic balance 1 and the poor performance of the electronic balance 1 can be easily understood by the user.

  As described above, the user can see the time-dependent fluctuation of the environmental measurement data and the time-dependent fluctuation of the measurement data, span value, and standard deviation of the span value as a time-series graph. The relationship between the performance defect of the electronic balance 1 and the environmental change can be immediately recognized, and the reliability of the user to the electronic balance 1 is increased.

  Further, the user can know from the correlation monitoring diagrams of FIGS. 3 to 6 that the fluctuation of the measurement data, the span value, and the standard deviation of the span value is caused by an increase in humidity, a decrease in atmospheric pressure, and an increase in temperature. Therefore, the user himself / herself can move to maintain the surrounding environment of the electronic balance 1 such as not stopping the air conditioner when leaving and keeping the humidity constant.

  And since the basic performance (accuracy) presented by the electronic balance 1 is maintained by such an environmental improvement by the user himself, an improvement in measurement accuracy can be achieved from a new viewpoint (cutting edge) that has not existed before.

  In addition, in the correlation monitoring chart of the standard deviation of the span value (FIG. 6), the error (standard deviation) is around 10 μg (about 0.01 mg) around 17:00 on December 3, so the user can Referring to the monitoring chart, it can be seen that the maximum performance (minimum display) obtained in the current environment is 0.01 mg. That is, at this time, the user makes a judgment on the spot such as stopping the measurement if the required measurement accuracy is 1 μg (0.001 mg) or continuing the measurement because there is no problem if the required measurement accuracy is 0.1 mg. Because it becomes possible, it is user friendly.

  From the above, when the basic performance of the electronic balance 1 does not come out, the user does not know whether the cause is a poor performance due to the installation environment or the poor performance of the weighing device main body, and whether the measurement can be continued, This eliminates the anxiety that the measured value can be trusted and the distrust of the mass meter itself, leading to the recovery of the confidence of the mass meter manufacturer.

  In addition, although the standard deviation of the span value is displayed as the standard deviation in the lower part of FIG. 6, the standard deviation obtained by repeatedly measuring the zero point and the weighing may be displayed. It is possible to know how reliably the weighing data is reproduced by monitoring the time-dependent fluctuation of the zero point and the standard deviation of the weighing data. Therefore, even if the zero point and the standard deviation of the weighing are displayed in correlation, the user generally sees the correlation monitoring chart, and the standard deviation indicating reliability generally increases, for example, the decrease in atmospheric pressure and It can be seen at a glance from the figure that it is caused by an increase in humidity. Therefore, even when the zero point and the standard deviation of the weighing are displayed in correlation, the standard deviation of the span value that makes it easier for the user to understand the correlation between the change in the surrounding environment of the electronic balance 1 and the performance failure of the electronic balance 1. The same effect as when using is obtained.

  Similarly, in the lower part of FIG. 3, the zero point is displayed as the weighing data, but the weighing may be displayed as the weighing data.

  FIG. 7 is a flowchart of the environment evaluation mode according to the second embodiment.

  In the second embodiment, an influence degree evaluation function for determining which environmental parameter has the highest influence degree on the measurement data or the like is added to the external CPU 32 using the configuration in the first embodiment. That is, as shown in FIG. 7, in the second embodiment, the influence evaluation flow after step S8 is added to the environment evaluation mode in the first embodiment.

  When the environmental evaluation mode is entered, as in the first embodiment, in steps S1 to S7, the environmental measurement data of temperature, humidity, and atmospheric pressure and the measurement data of the internal weight 5 are sampled, and the environmental measurement data, the measurement data, and the span are sampled. The standard deviation of the value and span value is monitored by correlation.

  Next, in step S8, it is determined whether or not the calculated standard deviation satisfies the basic performance (standard deviation 2.5 μg). If YES (standard deviation is 2.5 μg or less), the process proceeds to step S10, and only the correlation monitoring diagram is displayed on the monitor 31 as in the first embodiment, and the environment evaluation mode ends. On the other hand, when it is determined NO (standard deviation exceeds 2.5 μg), the influence degree of the environmental parameter is determined by the influence degree determination means in step S9. In step S9, for example, the amount of change per unit time of each numerical value is obtained from each monitoring data, and correlation analysis is performed. For each of zero point fluctuation, span value fluctuation, and span value standard deviation fluctuation, each environmental element ( The correlation coefficient r of temperature, humidity, and atmospheric pressure is obtained, and the degree of influence of the environmental parameter is evaluated as the environmental element having the greatest influence in descending order of the absolute value of the correlation coefficient r. In step S10, when the determination result (evaluation) obtained in step S9 is displayed on the monitor 31 together with the correlation monitoring diagram, the environment evaluation mode ends.

  By presenting such an evaluation to the user, the user can know which environmental parameter has the highest degree of influence, and the amount of change in the environmental measurement data is also disclosed. Can know if it should be improved. Therefore, for example, it can be estimated how much the temperature management is improved and the measurement data enters the target management width, and the user can move more specifically to the environmental improvement.

  Alternatively, the minimum display of the measurement value that can be determined in the current environment is estimated from the correlation coefficient r obtained by the influence determination means, and the digit for which the display or accuracy cannot be guaranteed is deleted / flashing. And present it to the user. As a result, the electronic balance 1 automatically suggests the current maximum performance (minimum display) that can be recognized with reference to the standard deviation in the first embodiment, so it is easier to determine whether or not to continue the measurement. It becomes.

  In the second embodiment, the standard deviation of the span value is used as the standard deviation used for the influence evaluation. However, the determination may be made based on the zero point or the standard deviation of the weighing instead.

  It is also effective to detect vibration by adding an accelerometer 14 to the environmental elements detected by the environmental sensor 10 in the first and second embodiments in addition to the temperature, humidity, and atmospheric pressure. The electronic balance with high weighing accuracy shown in the examples is sufficiently affected by the shaking of the ground that is not felt by human beings for a while after the earthquake has converged, as well as the occurrence of an earthquake, and the shaking caused by people coming and going Therefore, if a measurement is performed in an environment with even slight fluctuations, a measurement error occurs. Of course, it is possible to detect wind, sound pressure, gravity and the like as other environmental elements and incorporate them into the embodiment.

  In the first and second embodiments, not only the environmental sensor 10 but also the data logger 20 may be built in the electronic balance 1. Alternatively, instead of the data logger 20, an internal memory that is normally built in the electronic balance 1 may be used as the storage means of the present application. Similarly, the functions of the external PC 30 may be borne by the configuration of the electronic balance 1. That is, the processing in the external CPU 32 may be performed by the internal CPU 3, and the correlation monitoring diagram and the evaluation displayed on the monitor 31 may be displayed on the measurement value display unit 4. Thereby, all the devices constituting the weighing device are built in the mass meter, the configuration around the main body of the electronic balance 1 is simplified, the weighing device is unitized, and the user-friendliness is improved.

  In addition, the display method of the correlation monitoring diagram in the first and second embodiments may be in any display format as long as the display is correlated so as to correspond on the same time axis.

  Further, the correlation monitoring diagrams in the first and second embodiments may be configured to be displayed on paper output from a printer connected to the external PC 30 as necessary. That is, the display unit may be visually recognized through paper.

1 Electronic balance (mass meter)
2 Load measurement mechanism 3 Internal CPU
4 Display unit for displaying measurement values and the like as in the past 5 Built-in weight 6 Built-in weight addition / removal mechanism 7 Motor 8 Motor drive circuit 10 Environmental sensor (environmental measurement means)
20 Data logger (memory means)
30 External PC
31 External PC monitor (display section)
32 External CPU (arithmetic processing unit)
100 Weighing device

Claims (5)

A load measuring mechanism for detecting weighing data;
Environmental measuring means for detecting a physical quantity of the environment in which the load measuring mechanism is installed;
Storage means for storing weighing data detected by the load measuring mechanism and environmental measurement data detected by the environmental measurement means;
An arithmetic processing unit that performs arithmetic processing using the weighing data and the environmental measurement data stored in the storage means,
The arithmetic processing unit records and displays a time-dependent change in each of the zero point, which is a measurement value at no load, and the environmental measurement data as the measurement data.
A load measuring mechanism for detecting weighing data;
Environmental measuring means for detecting a physical quantity of the environment in which the load measuring mechanism is installed;
Storage means for storing weighing data detected by the load measuring mechanism and environmental measurement data detected by the environmental measurement means;
An arithmetic processing unit that performs arithmetic processing using the weighing data and the environmental measurement data stored in the storage means,
The arithmetic processing unit, as the measurement data, each of the span value, which is a difference between a measurement value when a load having a known mass is measured and a zero point which is a measurement value at no load, and the environmental measurement data over time. A weighing device that records and displays changes.
The weighing apparatus according to claim 2, wherein the arithmetic processing unit calculates a standard deviation of the span value, and records and displays the environmental measurement data.
The weighing apparatus according to claim 1, wherein the arithmetic processing unit obtains a standard deviation of the zero point, records and displays the environmental measurement data.
  The weighing apparatus according to claim 1, wherein the environment measuring unit is provided in a mass meter having the load measuring mechanism.

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