JPH0749990B2 - Electronic balance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an electronic balance.

<Prior art> Generally, in electronic balances, in order to stabilize the weighing display value against a disturbance such as vibration, it is performed to average a large number of load data from the load detecting unit to obtain a weighing value. ing. The number of times of averaging or the time for averaging data to be used for averaging (average time) is usually configured so that it can be selected according to the magnitude of disturbance in the installation environment, required measurement accuracy, and the like. It is needless to say that the installation environment should be in a place where there is as little disturbance as possible, such as vibration, and the less disturbance there is, the more accurate the measured value is in the state where the averaged number is reduced and the response is improved. Can be obtained.

<Problems to be solved by the invention> From the above, when installing an electronic balance, it is first necessary to determine which place is the most appropriate place with the least disturbance such as vibration. Often, humans make their decisions by relying on intuition based on the sense of touch.
However, even if it is not felt by humans, there is a degree of disturbance that affects a high-precision electronic balance, and thus the conventional method for determining the installation location as described above has a great problem.

Further, the disturbance situation is not always constant at the installation place once determined, and therefore, in a conventional electronic balance, it is always installed in an appropriate place and used based on an appropriate averaged number. It is hard to say that it is.

The present invention has been made in view of the above, and the electronic balance itself has a function capable of displaying the degree of the magnitude of the disturbance at the installation place, so that the optimal place to install without relying on intuition is the electronic balance. The purpose of the present invention is to provide an electronic balance that can detect this even when the situation of disturbance has changed after installation or after the installation.

<Means for Solving Problems> The configuration of the present invention will be described based on the functional block diagram shown in FIG.

The load detection unit a generates an electric signal corresponding to the mounting load,
The digital conversion data is supplied to the average value calculating means b at predetermined time intervals. The average value calculation means b determines the metric value by averaging the data based on the selected average number. The measured value is displayed by the measured value display means c. The digital conversion data from the load detector a is also taken into the data stability determination means d and the data variation calculation means e. The data stability determination means d determines whether or not the digital conversion data from the load detection unit a is in a stable state, and the data variation calculation means e sets in advance when the data is determined to be in a stable state. A value related to the magnitude of the variation of the predetermined number of data is calculated. The variation display means f displays the information based on the calculation result as information indicating the degree of disturbance at the installation location of the balance.

Here, the value related to the magnitude of the variation of the data refers to the standard deviation of the predetermined number of data, the variation width of the predetermined number of data (difference between the maximum value and the minimum value of the predetermined number of data), Further, the display content by the variation display means f is not limited to the above value calculated by the data variation calculation means e, an arbitrary coefficient indicating a data variation state based on the calculation result, and also a stepwise step based on the calculation result. Including various notification modes.

<Operation> In the stable state of the digital conversion data from the load detection unit a, that is, in the state where the load placed on the load detection unit a is not changed, the digital conversion data is only due to the disturbance acting on the balance. fluctuate. Therefore, the calculation result of the value relating to the magnitude of the variation of the predetermined number of data in the data stable state becomes the information indicating the degree of the disturbance at the installation location, and this balance is placed from the display content of the variation display means f. It is possible to know the magnitude of the external disturbance at the current location.

<Example> An example of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of the embodiment of the present invention.

The load detection unit 1 outputs an electric signal corresponding to the load placed on the dish 1a, and its digital conversion data is taken into the control unit 2 at every predetermined minute time. The control unit 2 is composed of a microcomputer, in which a CPU 21 for executing various calculations and programs and controlling each peripheral device, a measurement program, and a disturbance condition measurement program described later are written.
ROM22, an area for storing digital conversion data from the load detection unit 1 and an area for storing various calculation results
RAM23 and I / O port 24 for connection with external devices
Etc., which are connected to each other by a bus line.

At the input / output port 24 of the control unit 2, in addition to the load detection unit 1, a key switch 3 for giving a command to the control unit 2 and a display for digitally displaying a measured value and the like according to a command from the control unit 2. 4 is connected.

As shown in FIG. 3, a front view of the display unit 4 shows a measured value display unit 4a for displaying a measured value and a disturbance condition display unit 4b for displaying a standard deviation σ calculated by a disturbance condition measurement program described later. Is equipped with.

Next, the operation will be described. The measurement program is executed in the normal measurement mode. In this measurement program, RA
Among the data from the load detection unit 1 stored in M23, the latest number of the number selected by the key switch 3 is averaged to determine the load weight value on the dish 1a and display it. Display in 4.

When the disturbance condition measuring mode is selected by the key switch 3, the disturbance condition measuring program shown in the flowchart of FIG. 4 is executed.

In the disturbance condition measurement program, first, it is determined whether or not the data from the load detection unit 1 is changing. This is the load detection unit 1 that accompanies loading and unloading the load on the plate 1a.
The step response of the output of is not contained, the disturbance situation cannot be measured during the data change, so the step response is completely contained, and the process proceeds to the next step after the data is in a stable state. This determination can be performed by using a known stability determination method. For example, when the value of each data is within a predetermined width with respect to the average value of a predetermined number of data, the data is stable. It can be determined that there is a state.

In the data stable state, the preset N data are fetched from the data group from the load detection unit 1 stored in the RAM 23, the standard deviation σ of the N data is calculated, and the value is calculated. Is displayed on the disturbance condition display portion 4b of the display unit 4. Since the variation of the data in the stable state of the data is considered to be due to the disturbance acting on the electronic balance, its standard deviation σ has a close correlation with the magnitude of the disturbance at this installation location, and the magnitude of the disturbance is large. It is an effective guide for comparing the height. Therefore, when deciding the installation location of the electronic balance, this electronic balance is installed at each of a plurality of candidate locations, the standard deviation σ values at each location are compared, and the location having the smallest value is selected. This makes it possible to find the most suitable installation location. Also, in the electronic balance once installed, changes in the surrounding disturbance condition can be known from the displayed value of the standard deviation σ.

In the above embodiment, the variation state of N pieces of data is represented by the standard deviation σ. However, by obtaining the width of the variation of N pieces of data and displaying it, it is possible to estimate the disturbance situation. Further, it is also possible to obtain a coefficient related to the magnitude of the disturbance based on the variation state of the data without displaying them directly, and to display this. It is also possible to divide the magnitude of the disturbance into a plurality of stages and display the stage based on the magnitude of the variation of the data, instead of displaying.

Further, in the above-described embodiment, the execution of the disturbance condition measuring program is instructed by the mode selection by the key switch 3, but the program may be automatically executed when the power is turned on, for example.

<Effect> As described above, according to the present invention, the stable state of the digital conversion data from the load detection unit 1 is determined, and the value related to the magnitude of the variation of the predetermined number of data in the stable state of the data is calculated. Since it is configured to display information according to the calculation result, the user of the balance can know the magnitude of the disturbance at the place where the electronic balance is installed based on the displayed content. The optimum place where this electronic balance should be installed can be determined while quantitatively grasping the magnitude of the disturbance without relying on intuition as in the conventional case. Similarly, even for an electronic balance that has already been installed, it is possible to quantitatively grasp the change in the disturbance situation at that location, and use it as a guide for whether or not it is necessary to change the averaged number.

[Brief description of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, FIG. 3 is a front view of its display unit 4, and FIG. It is a flow chart which shows a disturbance situation measurement program written in ROM22. 1 ... Load detection unit 2 ... Control unit 3 ... Key switch 4 ... Display unit 4a ... Weighing value display unit 4b ... Disturbance status display unit 21 ... CPU 22 ... ROM 23 ... RAM 24 ... I / O port

Claims (1)

[Claims] 1. A weighted value is determined and displayed by sampling digital conversion data from a load detection unit at predetermined time intervals and calculating an average value of the data based on the selected averaged number. In the balance, means for determining the stability of the data, means for calculating the value related to the variation size of a predetermined number of preset data in the stable state of the data, and the balance installation location based on the calculated value An electronic balance comprising means for displaying the degree of disturbance.