JPS6031023A - Electronic counting scale - Google Patents

Abstract

PURPOSE:To count the number of samples quickly and accurately, by preventing the updating of the average weight of samples until the number of added samples exceeds the maximum allowable number of added samples, and making the constitution and operation simple. CONSTITUTION:Samples 1, whose number is known, are mounted on a measuring pan. The known number and the dispersion data of the sample weights are inputted from the keyboard 7 of a control part 9. The average weight of the sample and the maximum number of addition of the sample without counting errors are counted by a CPU4 and stored in an RAM6 and the like. The number of the added samples is counted by the following measurements of the added samples and the average weight in the RAM. At this time, whether the number of the added sample exceeds the maximum allowable number or not is judged by the CPU. Unless the added number exceeds the allowable number, the average weight in the RAM6 is not updated. When it is exceeded, alarm is generated. Therefore the average weight is not required to be computed at every measurement, and the constitution and operation can be made simple. Thus the number of the sample can be counted by an electric counting scale quickly and accurately.

Description

[Detailed description of the invention] (b) Industrial application fields The present invention relates to electronic counting scales.

(b) Prior art In a counting scale that counts the number of samples by dividing the weight of a large number of samples of the same type by the average weight per sample 1111, how to eliminate counting errors caused by variations in the weight of individual samples. This is an important issue.

In Japanese Patent Application No. 57-54239, the present applicant previously calculated information regarding variations in sample weight, such as the coefficient of variation and standard deviation of sample weight, and updated the average weight per sample each time additional samples were counted. At the same time, they proposed an electronic counter that has a means to calculate the maximum allowable number of additional items that can be counted next time without including counting errors. However, there are cases where the variation in weight values is known, and even in that case, it is wasteful to perform the weighing operation multiple times to calculate the variation in weight values.

(c) Objective Accordingly, an object of the present invention is to provide an electronic counting scale that can count the number of samples without causing counting errors from the beginning.

(D) Structure In order to achieve the above object, the electronic counting scale according to the present invention includes a weight value variation information input means for inputting information regarding variation in individual sample weights, and a weight value variation information input means for inputting information regarding variation in individual sample weights, and a weight value variation information input means for dividing the loaded sample weight by the number of samples. an average weight calculation means for calculating the average weight per sample; and a means for calculating the maximum allowable additional number of samples that can be additionally counted with zero counting error based on the information regarding the variation in sample weight and the number of already counted samples. ,
The apparatus includes means for calculating the number of additional samples from the number of added samples and the average weight, and means for determining whether the number of additional samples exceeds the allowable maximum number of additional samples.

(e) Examples Examples of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a diagram showing the configuration of this embodiment, and FIG. 2 is a flowchart explaining the operation.

In FIG. 1, the weighing value output unit 3 of the electronic balance system outputs the weight value of the sample placed on the weighing pan 2, and the value is C
The data is input to a control section 9 consisting of a PU 4, a ROM 5, a RAM 6, a keyboard 7 and a display section 8. The ROM 5 stores a program corresponding to the flowchart shown in FIG. 2, which defines the operation of this embodiment. In the above configuration, first, the coefficient of variation Cv (known) of each weight value of the sample to be counted is input from the keyboard 7 (step 21 of the flowchart in FIG. 2). Next, when a sample with a known number of pieces is placed on the weighing pan 2 and the number of pieces is entered from the keyboard 7 (step 22), the CPU 4 calculates the average per sample from the sample weight WO output from the weighed value output section 3 and the number of samples. Calculate weight X0-Wo/No (step 23),
Next, the coefficient of variation Cv and the number of samples No. that were input earlier
Therefore, the first allowable maximum addition number PI' that can be added without causing a counting error is calculated based on the formula % (%), and the value is displayed (n=1 in step 24). When an unknown number of samples estimated to be less than or equal to the allowable maximum additional number P1 is added (step 25), the additional sample weight Ml = the difference between the weight of No samples Wo before addition and the sample weight W1 after addition. wl-wQ is determined (n=1 in step 26), divided by the average weight per sample X() determined earlier in step 23, and P+ = M1/To (rounding the fraction) is the number of additional pieces. Calculated as , and add the number of already counted items (No in this case)
is added, and the value obtained by subtracting the tare value N-r (the value obtained by converting the tare weight to the number of samples - described later) is Nn = Pn.
+Nn-+-NT (n-1 in this case) is displayed (
Step 27). However, while no sample is added in step 25, Pn is calculated as Pl=0 in step 27, and as a result, the process passes through the YES branch of the next decision step 28, and returns to step 25 via step 35. return. In step 35, the tare value NT is p n + Nn-1 or zero (
Tare=initial value=0). Therefore, the number of counted samples (No in this case) can be displayed in step 27 even if no sample is added in step 25 or even if only the sample tare is loaded. If samples are added in step 25, step 28 proceeds to step 29, where it is determined whether the number of samples to be added exceeds the allowable maximum number of samples to be added, and if it does, an alarm is issued (step 34). The process returns to step 25 via step 35 (6), and if not exceeded, the process proceeds via step 30 to step 32 where sample 1
The average weight per piece is updated.

If additional counting is to be performed, step 33 is N.

The process returns to step 24 from the branch n-2゜3,
-, the above process is repeated until counting of a predetermined number of objects is completed. After the weighing operation is completed, an offset setting operation is performed, and in step 36, the device percentage processing is performed.

The present invention can also be implemented by modifying some of the steps in the calculation process as shown in the flowchart shown in FIG. In this embodiment, when continuing the weighing operation of the same type of sample after completing a series of weighing operations for a predetermined number of samples,
Until the number of samples that increases each time a sample is added in the weighing process exceeds the maximum value of the number of samples completed in the previous process, the weighing time can be reduced by omitting the step of updating the average weight per sample. is being shortened. In the flowchart shown in FIG. 3, step 31 is inserted between step 30 and step 32 of the flowchart in FIG. 2, and step 32 is changed to step 32a accordingly. In step 31, in the process of several weighing operations, the number of samples Nn is equal to the maximum value Nma of the number of samples completed in the previous weighing process.
This is the step of determining whether the value exceeds x. Therefore,
In the first weighing operation, Nmax is zero, and for each additional count, the process always passes through the YES branch of step 31, based on the flowchart of FIG. Step 32a
Counting is done in the process of passing through. When the predetermined number of pieces has been weighed, the first predetermined number is Nmax and R is
AM6 (FIG. 1). Next, when performing a second weighing operation, as long as the number of samples Nn is less than or equal to Nmax, step 31 goes NO, and the process goes from step 35 to step 25, and the counting process is repeated without updating the average weight. If Nn exceeds Nmax, step 31 passes through the YES branch and proceeds to step 32a. From then on, Nmax is updated every time a sample is added, and this step 32a
Then, the average value is updated based on the formula Xn=Wn/Nmax.

When weighing is completed, the final number of pieces to be weighed is Nmax.
remains in RAM6 as In addition, if the final number of pieces to be weighed in this weighing operation process is less than the first number of pieces to be weighed, the final number of pieces to be weighed for the first time will be Nma.
x remains stored in the RAM 6, and Nmax is not updated with the second final weighing number.

Furthermore, the present invention can be implemented such that the above-mentioned Nmax is updated with the final number of items weighed at that time each time the weighing operation is completed. In such embodiments,
Updating the average value is executed every time a measurement is completed, and is effective in preventing counting errors due to slight drifts in sample weight during sample manufacture, even when samples of the same type are weighed.

The present invention can also be implemented by changing steps 21 and 23, which are common to all the embodiments described above, to steps 21a and 23a, respectively, in the partial flowchart shown in FIG. In this embodiment, the standard deviation So (known) of sample weight values is first input in step 21a, and the average sample weight Xo and coefficient of variation Cv of the known number NO are determined in step 23a.

(Effect) As is clear from the above explanation, by first inputting the variation coefficient or standard deviation of the sample weight, which is information regarding the variation in sample weight, the configuration and operation are simplified compared to conventional devices. Moreover, by omitting a part of the average value updating process without affecting accuracy, an electronic counting scale can be obtained in which the time required for counting is shortened.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a flowchart showing the contents of a program of the embodiment. FIG. 3 is a flowchart of another embodiment of the invention, and FIG. 4 is a flowchart of still another embodiment of the invention. 1- Sample 2- Weighing pan 3- Weight value output section 4- CPU 5- ROM 6- RAM 7- Keyboard 8- Display section 9- Control section Patent applicant Shimadzu Corporation Agent Patent attorney 1) New (I+)

Claims (1)

[Claims] means for calculating the average weight calculation means for calculating the above-mentioned information regarding the variation in sample weight and the maximum allowable additional number of samples that can be additionally counted with zero counting error from the information regarding the variation in sample weight and the above-mentioned number of samples; It has a means for calculating the number of additional samples from the average weight and a means for determining whether the number of additional samples exceeds the above-mentioned maximum allowable additional number of samples. An electronic counting scale configured such that the average weight calculating means updates the average weight of the samples each time a specific number is exceeded. (2) The specific number of samples to be additionally loaded has already been loaded before adding the sample. The electronic counting scale according to claim 1, characterized in that the specific number of samples to be additionally loaded is the final number counted in each preceding series of counting processes. The electronic counting scale according to claim 1, wherein the specified number of samples to be additionally loaded is the maximum value of the number of samples measured. The electronic counting scale according to claim 1, characterized in that it is the final number of items measured in the counting process.