JPH084578Y2 - Electronic balance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electronic balance, and more specifically to an electronic balance having an automatic sensitivity calibration function.

<Prior art> Generally, an electronic balance having an automatic sensitivity calibration function has a built-in weight for sensitivity calibration and its addition / removal mechanism, and when a certain time has elapsed or a certain temperature change has occurred since the last calibration. In addition, a calibration command is automatically generated, the built-in weight is loaded on the load detection unit, and the sensitivity coefficient is updated from the output at that time and the weight mass stored in advance.

<Problems to be solved by the invention> By the way, in an electronic balance, particularly a high-precision electronic balance, even if the sensitivity is calibrated when there is a certain temperature change, the temperature difference for issuing the sensitivity calibration command is Unless is set to be infinitely small, there will be a difference in the measured value immediately before and after the sensitivity calibration. Similarly, even when sensitivity calibration is performed after a certain period of time, a difference occurs in the measured values immediately before and immediately after the sensitivity calibration.

Therefore, if you want to make more accurate measurements,
Even if you use a balance with the automatic sensitivity calibration function as described above, the measurer will perform sensitivity calibration immediately before starting measurement without relying on that function, and as a result, the advantage of having the automatic sensitivity calibration function is obtained. I will be scarce.

An object of the present invention is to provide an electronic balance having an automatic sensitivity calibration function, which can utilize the function more effectively.

<Means for Solving the Problems> A configuration for achieving the above object will be described with reference to the basic conceptual diagram shown in FIG. 1. In the present invention, a built-in weight a, its addition / removal mechanism b, and sensitivity calibration are used. In a balance having a calculation means c and having a function of automatically performing sensitivity calibration when a calibration command is issued, a clock function d, a time data input means e, a storage means f of the input data, and a storage content thereof. And a time-matching detection means g according to the clock function d, and is configured to generate a calibration command at the time of matching detection.

<Operation> By inputting a desired time in advance by the input means e, the sensitivity calibration is automatically executed when the time is reached. For example, when performing a measurement at a certain time every day, the sensitivity calibration operation will always be automatically performed immediately before the actual measurement depending on the usage method such as inputting the time immediately before that. The desired purpose can be achieved.

<Embodiment> FIG. 2 is a block diagram showing a configuration of an embodiment of the present invention.

The load detection unit 1 outputs an electric signal corresponding to the load acting on the load sensitive unit including the dish 1a, and the output is digitized by the AD converter 2 and then taken into the control unit 3.

A weight adding / removing mechanism 4 is disposed in the vicinity of the load detecting unit 1. The weight adding / removing mechanism 4 uses the known mechanism such as a lever, a cam, and a drive motor thereof to load or load the built-in weight 5 on the load sensitive unit. It can be canceled. The drive command of the weight adding / removing mechanism 4 is given from the control unit 3.

A temperature sensor 6 is arranged in the load detection unit 1, and the output of the temperature sensor 6 is also digitized by the A / D converter 2 and then taken into the control unit 3. The input stage of the A / D converter 2 is provided with a switch 7 for switching the input signal in order to alternately digitize the output of the temperature sensor 6 and the output of the load detection unit 1 at a predetermined interval. The drive of this switch 7 is also controlled by a signal from the control unit 3.

The control unit 3 is mainly composed of a microcomputer, and includes a CPU 31, a ROM 32, a RAM 33, a non-volatile RAM 34, an input / output interface 35, and the like, for displaying a measured value in addition to the A / D converter 2 described above. Indicator 8 of
A keyboard 9 for inputting arbitrary time data is connected. The microcomputer of the control unit 3 has a backup power source and has a clock function.

In the ROM 32, in addition to the normal measurement program and the sensitivity calibration program, a calibration start time monitor program to be described later is written.

The RAM 33 is set with a work area, an area for storing load data taken from the load detection unit 1 every moment, and the like.

An area for storing the time data input from the keyboard 9 is set in the nonvolatile RAM 34, and this time data is used as the calibration start time data in the calibration start time monitor program.

Among the programs written in the ROM 32, the normal measurement program and the sensitivity calibration program are known ones, and a detailed description thereof will be omitted. However, in the measurement program, the program from the load detection unit 1 is used. At the same time as calculating the weighing value to be displayed on the display unit 8 by incorporating the digital conversion data every moment, whether or not there is a specified temperature change and whether or not a specified time has elapsed from the time of the last calibration. The determination is always made, and if any of these is found, a calibration command is issued. Then, when the calibration command is generated, the sensitivity calibration program is executed. In the program for sensitivity calibration, the weight adding / removing mechanism 4 is driven to load the built-in weight 5 on the load sensitive section, and the sensitivity coefficient is calculated from the output value of the load detecting section 1 at that time and the weight mass stored in advance. Update.

FIG. 3 is a flow chart showing the contents of the calibration start time monitor program written in the ROM 32. The operation of the embodiment of the present invention will be described below with reference to this figure.

This program is executed in series with the measurement program when the main power supply of the device is on, and only this program is executed by the backup power supply when the main power supply is off.

When the time to use this balance has been determined, the user of the balance inputs the time or a time slightly earlier than that time using the keyboard 9.

Now, if the main power is not turned on, it is non-volatile
The time stored in the RAM 34 is compared with the current time (ST2), and the routine returns to ST2 via ST3 and waits until that time is reached. When the time in the nonvolatile RAM 34 is reached, the program proceeds from ST2 to ST6 to automatically turn on the main power source, and then executes the sensitivity calibration program (ST
7).

When the main power is on, the measurement program is being executed, and this program is executed at the end of the routine. Similarly, in ST2, the nonvolatile RAM 34
Whether or not the time stored in the memory has been reached is discriminated. If the time has not been reached, the process proceeds to ST4 via ST3 and returns to the start point of the measurement program.

When it is determined in ST2 that the time has been reached, it is determined whether or not the measurement is in progress in ST9 through ST5, that is, whether or not the sample is placed on the dish 1a, and there is no load. In this case, proceed to ST7 and execute the sensitivity calibration program.

If ST9 determines that the measurement is in progress, set a flag (S
T10), proceed to ST4 without sensitivity calibration. Then, thereafter, from ST1 to ST11, it is determined whether or not the measurement is being performed, and when the measurement is completed, the flag is cleared (ST12),
Proceed to ST7 to execute the sensitivity calibration program.

In each of the above cases, when the sensitivity calibration is executed in ST7, that effect is displayed on the display 8 in ST8. As a result, the measurer can confirm that the sensitivity calibration has been performed as scheduled, and can perform the measurement with confidence.

The display content in ST8 may be the time when the calibration is completed.

<Effect of Device> As described above, according to the present invention, the sensitivity calibration is automatically executed at a time arbitrarily set in advance by a keyboard or the like. If the time to use the balance is known, such as when measuring the weight, by entering the time, the sensitivity is automatically calibrated immediately before the start of measurement, and There is no need to calibrate the sensitivity before use.

By providing the function of the present invention together with the conventional function of automatically performing sensitivity calibration when a certain time elapses or a certain temperature difference occurs, the advantage of having an automatic sensitivity calibration function is more effective. Can contribute to the improvement of work efficiency.

Further, by displaying the fact that the sensitivity calibration is completed as scheduled at the reserved time, the measurer can carry out the measurement with confidence and the reliability is improved.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram showing the configuration of the present invention, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is its ROM 32.
5 is a flowchart showing the contents of a calibration time monitoring program written in the. 1 ... Load detection unit 3 ... Control unit 31 ... CPU 32 ... ROM 33 ... RAM 34 ... Non-volatile RAM 4 ... Weight adjustment mechanism 5 ... Built-in weight 9 ... Keyboard

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A balance having a built-in weight, a mechanism for adding and removing the weight, and a sensitivity calibration calculation means, and having a function of automatically performing the sensitivity calibration when a calibration command is issued. Storage means for input data,
An electronic balance having a match detection means for the stored contents and the time by the clock function, and configured to generate the calibration command at the time of the match detection.