JPH0121448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic counting scale that calculates the number of samples by dividing the sample weight by a reference weight.

In such electronic counting scales, the measurement accuracy of the reference weight (usually the average weight of 1 to 100 samples is used) is very important. Generally, in order to improve the measurement accuracy of electronic scales, it is necessary to take a long averaging time, and if the averaging time is too long, the displayed value may not respond sufficiently when the measured value changes from moment to moment. arise.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronic counting scale that measures the reference weight with sufficient accuracy and responds as quickly as possible during counting.

In order to achieve this objective, in the present invention, as shown in the basic conceptual diagram of FIG.
The sample weight determined based on the load data when operating the is stored in the reference weight memory c, and the sample weight determined based on the load data when an unknown number of samples is loaded on the load detection section a. In a scale equipped with a number calculation means d for calculating the number of samples using the contents of a reference weight memory c, a first weight value determination means e for determining the weight by averaging a predetermined number of load data; A second weight value determining means f is provided for determining a weight value by averaging a greater number of load data than the number of data averaged by the first weight value determining means e.

Further, a stability determining means g is provided for determining whether or not the load data from the load detecting section a is in a stable state.

The weight determined by the first weight value determination means e is used for the number calculation by the number calculation means d, and the sample weight to be stored in the reference weight memory c is determined by the second weight value determination means f. The weight is used and the storage operation in the reference weight memory c is performed after the reference weight setting key b is operated and after stability is determined by the stability determining means g.

Examples of the present invention will be described below.

FIG. 1 shows a block diagram of an embodiment of the invention. The load detection unit 1 momentarily converts the load on the weighing pan into a digital electric signal and outputs the digital electric signal. The CPU contains various registers for calculations, arithmetic units, a clock generator, etc., and controls each peripheral device via the bus line. ROM stores programs. RAM temporarily stores measured values, calculated values, etc. these,
The CPU, ROM, RAM, and bus line are configured by the microcomputer 2. The keyboard 3 includes a standard setting key, a tare key, and the like. The display 4 displays numerical values such as calculation results.

The measurement procedure according to this example is performed using a standard number of 10 pieces,
A case will be explained in which the average number of times before the reference setting key is pressed is 16 times and the average number of times after the key is pressed is 3 times.

First, place 10 samples on the weighing pan and immediately press the reference setting key. The weight of the 10 samples is displayed in grams. When the scale output becomes stable,
The average weight M obtained by dividing the average value of the 16 measurements by 10 is automatically stored in the memory. Here, it switches to 3 times average, and the display changes from weight grams to 10 pieces. Next, place an unknown number of samples. Since it is an average of three times, it responds promptly and displays the number. If the sample is dropped, O pieces will be displayed. As long as the sample does not change, the number will be displayed immediately just by placing the sample. When the sample changes, pressing the reference setting key again erases the average weight M and returns to the original state.

Figure 3 shows a flowchart of the program.

First, set the average number of times to 16 at step 11. Tare weight subtraction processing is executed and the display becomes "0 grams".
The latest data input from the load detection unit 1 is stored in area D ₁ of the RAM, and is sequentially processed.
It is shifted in the order of D ₁ → D ₂ →… → D ₁₆ , and the parts after D ₁₆ are discarded. 12, (Di→Di+ ₁ ) shows this shift operation. The average value W is calculated moment by moment,
This is displayed.

Before the reference setting key is pressed, judgment step 13 is executed.
If NO, steps 12→13 are repeated.

If 10 samples are placed here, the average value is calculated using equation (1), but when the standard setting key is pressed, judgment step 13 advances to YES, and when the data is stable, that is, the past 16 data When all of D ₁ to _{D 16} are within a predetermined stable range, for example within ±4 counts, judgment step 14 advances to YES and the next
At step 15, the average value W is stored in the reference weight memory M as a reference weight. Next, in step 16, the average number of times is changed from 16 times to 3 times. Step 17 executes a number calculation to calculate the number N of unknown samples.

When an unknown number of samples is placed on the weighing pan, the number calculation of equation (2) is executed and the number N is displayed. If the reference setting key is pressed again during this time,
At judgment step 18, it is judged that the sample has changed, and the process returns to the first step.

The reference setting key of the present invention is not specified only by its name; for example, in a counting scale with a built-in statistical calculation function, a key called a statistical memory key corresponds to this key. A flowchart when statistical processing is included in FIG. 2 is added in the branch line.

As a modified embodiment of the present invention, instead of setting the average number of times before pressing the reference setting key to 16 times,
After confirming that the display is within the stable range,
It may be configured such that the measuring person presses the switching key. Furthermore, the display may be erased until the scale output stabilizes before pressing the reference setting key, and the display may be performed when the scale output is stabilized.

Note that the number of pieces converted value is calculated by converting at least the number of counts of the scale's resolution (one count) into the weight of one sample. is displayed stably.

According to the present invention, the values used to calculate the calculated value of the reference weight, which is the most likely cause of error in a counting scale, include:
Since data with many errors that occur suddenly or data due to external disturbances such as vibration or wind are automatically excluded, an accurate reference weight can always be obtained regardless of the operator's operations. In addition, since the averaging time is automatically shortened when displaying the number of pieces, responsiveness is good and quick weighing work can be performed.

[Brief explanation of drawings]

Figure 1 is a basic conceptual diagram showing the configuration of the present invention;
The figure is a block diagram showing the configuration of an embodiment of the present invention.
The figure is a flowchart showing the contents of the program of the above embodiment. 1...Load detection section, 2...Microcomputer, 3...Keyboard, 4...Display device.

Claims (1)

[Claims] 1. The sample weight determined based on the load data when operating the reference weight setting key with a known number of samples loaded on the load detection unit is stored in the reference weight memory, and the unknown number of samples is loaded into the load detection unit. In a scale equipped with a number calculation means for calculating the number of samples using the sample weight determined based on the load data when a load is applied to the section and the contents of the reference weight memory, a predetermined number of load data are averaged. a first weight value determining means for determining the weight;
A second means for determining a weight value by averaging load data of a number greater than the predetermined number of the first weight value determination means.
weight value determining means, and stability determining means for determining whether or not the load data from the load detecting section is in a stable state; The determined weight is used, and the sample weight to be stored in the reference weight memory is the weight determined by the second weight value determining means, and the storage operation in the reference weight memory is performed according to the reference weight setting. An electronic counting scale characterized in that the electronic counting scale is configured to carry out the determination after a key is operated and after stability determination is made by the stability determining means.