JPH0749989B2 - Electronic balance - Google Patents

Description

The present invention relates to an electronic balance having an automatic sensitivity / sensitivity calibration function.

<Prior Art> In an electronic balance, generally, the digital data from the load detection unit is converted into a mass value using a calibration coefficient, and the measured value to be displayed is determined.

In such an electronic balance, when a preset time elapses or a temperature change occurs, the built-in weight of the balance is automatically loaded on the load detection unit and the load data and reference mass in that state are used. Some have a function to update the calibration coefficient, a so-called automatic sensitivity calibration function.

By the way, in sensitivity calibration, the ambient environment in which the balance is set has a great influence on the accuracy of the obtained calibration coefficient, and if the calibration is performed in a bad environment, the balance specifications may not be satisfied. is there. When the automatic sensitivity calibration function operates and the calibration coefficient is automatically updated, if the new calibration coefficient does not meet the specifications, the balance user may take measurements without noticing that. is there.

Therefore, in the conventional electronic balance having an automatic touch calibration function, it is determined whether the environment at the time of sensitivity calibration is sufficient to satisfy the specifications from the variation of load data at the time of sensitivity calibration, and if not satisfied, A warning is displayed to that effect, and measures are taken to notify the balance user.

<Problems to be Solved by the Invention> In the electronic balance having the conventional automatic sensitivity calibration function as described above, when the automatic sensitivity calibration function is activated while the power is on and not in use, the specification is caused by disturbance or the like. If the calibration that does not satisfy the condition is performed, a warning display to that effect is displayed, but the state is maintained as it is until the use is started.

If the balance installation environment is normally a good environment with no disturbance, the balance user will see some trouble in the balance if such a warning is displayed when trying to use the balance. There is a risk that you might think that it was a mistake.

In addition, if the automatic sensitivity calibration function works to perform sensitivity calibration but it does not satisfy the balance specifications, use the balance even if it has the automatic sensitivity calibration function. There is also a problem that the sensitivity must be manually calibrated again before the operation.

<Means for Solving the Problem> The electronic balance of the present invention is a calibration that determines whether the environmental condition at the time of calibration is within the preset allowable limit from the output data of the load detection unit at the time of sensitivity calibration. In addition to the environmental discrimination means and the display means for displaying a warning to that effect when the environmental state at the time of calibration is outside the allowable limit based on the discrimination result, the environmental state at the time of calibration based on the above discrimination result. If the value is out of the allowable limit, and if that state continues even after the preset time has elapsed from the time when the calibration was performed, the automatic sensitivity calibration function is reactivated at that point. Means are provided.

<Operation> When an automatic sensitivity calibration that does not meet the balance specifications is performed, a message to that effect is displayed, and if the state continues for a certain period of time, the automatic sensitivity calibration function is reactivated. If a calibration that does not meet the specifications was made due to a sudden disturbance during the initial automatic sensitivity calibration, it is highly likely that a sensitivity calibration that meets the specifications will be made by restarting, and the warning display disappeared before use. It will be in a state.

<Embodiment> FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

The load detection unit 1 includes an equilibrium mechanism 1b that engages with the dish 1a, a balance sensor 1c that detects the equilibrium state of the equilibrium mechanism 1b, and the detection result of the balance sensor 1c is always "equilibrium state".
The electromagnetic force generator is configured by the electromagnetic force generator 1d that is feedback-controlled to generate an electromagnetic force that maintains
1d outputs an electric signal proportional to the generated force.

In the load detection unit 1, a built-in weight 2 whose mass has been measured in advance and a weight addition / removal mechanism 3 for loading or unloading the built-in weight 2 with respect to the balance mechanism 1b are arranged.

The output signal of the electromagnetic force generation unit 1d is introduced into the AD converter 5 via the low-pass filter 4, digitized here, and then taken into the control unit 6.

The control unit 6 is mainly composed of a microcomputer, and has a CPU 6a, ROM 6b, RAM 6c and an input / output interface 6
A program described later is written in the ROM 6b having d and the like.

In addition to the A / D converter 5, the control unit 6 includes a display 7 for displaying a weighing value, a warning lamp 8 that is turned on when the environmental condition during automatic sensitivity calibration is bad, and the weight described above. The addition / removal mechanism 3 is connected.

FIG. 2 is a flow chart showing an excerpt of a characteristic part of the present invention from the program written in the ROM 6b.
The operation of the embodiment of the present invention will be described with reference to this drawing.

In the normal measurement routine with the power turned on,
If a preset time has elapsed from the time of the previous calibration, or if there is a certain temperature change from the time of the previous calibration, the automatic sensitivity calibration function works if measurement is not in progress at that time. In this automatic sensitivity calibration, the weight addition / removal mechanism 3 is driven to load the built-in weight 2 on the balancing mechanism 1b, and the output change of the AD converter 5 at that time and the mass value of the built-in weight 2 stored in advance. From then, it is performed by updating the calibration coefficient.

When such an automatic sensitivity calibration routine is completed (A),
It is determined whether or not the degree of variation in the load data from the AD converter 5 taken in during the sensitivity calibration is within a range that satisfies the preset balance specifications (B), When satisfied, the warning lamp 8 is not turned on and the normal measurement routine is returned to (C, D).

When it is determined in step B that the degree of variation in the load data is outside the above range, the warning lamp 8 is turned on (E), and at the same time, the timer is set to N (F), and thereafter the value becomes 0. Until then, the value N of the timer is decremented by 1 (G, H).

When the timer value becomes 0, that is, after the automatic sensitivity calibration that does not satisfy the specifications is performed and a certain period of time elapses, the automatic sensitivity calibration is executed again (I), and the calibration operation ends. For example, as in the last time, steps B and below are executed.

As described above, when it is determined that the data when the automatic sensitivity calibration function is activated has a variation that does not satisfy the balance specifications, the automatic sensitivity calibration is automatically executed again after waiting a certain period of time. This operation is repeated until the balance specifications are satisfied.

Here, the time set by the timer is significantly shorter than the time during which the normal automatic sensitivity calibration function operates, and it is preferable to set it to, for example, several minutes.

<Effects of the Invention> As described above, according to the present invention, when the automatic sensitivity calibration function operates, if the data provided for the calibration is dispersed to the extent that the balance specifications cannot be satisfied, a predetermined time Since the sensitivity calibration is automatically executed again later, it is highly possible that this recalibration will perform the calibration that satisfies the specifications, for example, when the sensitivity calibration that does not satisfy the specifications is performed due to a sudden disturbance or the like. For example, when a measurement is to be performed after being left for a long time, there is a high possibility that the calibration always satisfies the specifications. as a result,
Unlike the conventional method, it does not cause the balance user to worry about whether or not a trouble has occurred, and since the probability of a normal calibration state at the beginning of measurement is improved, the automatic sensitivity calibration function Becomes significant.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the embodiment of the present invention, and FIG. 2 is a flow chart showing the main part of the program written in the ROM 6b. 1 …… Load detection unit 1a …… Plate 1b …… Balance mechanism 1c …… Balance sensor 1d …… Electromagnetic force generation unit 2 …… Built-in weight 3 …… Weight adding / removing mechanism 4 …… Low-pass filter 5 …… AD conversion Unit 6 ... Control unit 6a ... CPU 6b ... ROM 6c ... RAM 6d ... I / O interface 7 ... Display unit 8 ... Warning lamp

Claims (1)

[Claims] 1. A calculation unit for determining a weighing value from output data of the load detection unit in a measurement state by calculation using a calibration coefficient, and the load detection unit automatically when a preset condition is satisfied. In the balance equipped with automatic sensitivity calibration means for loading the calibration mass on the, and calculating and updating the calibration coefficient from the output data of the load detection unit in that state, the output data of the load detection unit at the time of sensitivity calibration. From the calibration environment judgment means for judging whether the environmental condition at the time of calibration is within the preset allowable limit, and if the environmental condition at the time of calibration is outside the allowable limit based on the judgment result, When the environmental condition at the time of calibration is out of the allowable limit based on the above-mentioned discrimination result and the display means for displaying the warning of Electronic balance, characterized in that it comprises means for re-operating the automatic sensitivity calibration means when that state continues at point.