JPS6024406B2 - electronic balance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic force automatic balancing type electronic husband bottle that has a built-in microcomputer to control weighing functions and perform data processing and calculations.

It is generally well known that in order to accurately measure weight using an electronic bottle, it is necessary to wait approximately 3 minutes or more after turning on the power before weighing.

This is to prevent changes in the zero point indication of the two bottles due to self-heating and temperature rise of the many electronic components that make up the device immediately after the power is turned on, thereby preventing the measurement value from being affected. In addition to the above, the zero point of the cap may gradually shift slightly due to changes in the level of the hem of the cap, the influence of external factors such as vibration, changes in temperature, convection generated from the air conditioning in the measurement room, etc. . Even if this minute change in the zero point is a minute amount that can be ignored in measurement, it is customary for the measurer to manually correct the zero each time and confirm the zero before weighing. Since the manual zero adjustment operation for minute changes that is performed each time a measurement is troublesome, a zero point minute automatic correction device has been devised to keep the above minute changes within a predetermined minute range, that is, to the point where it can be ignored for measurement purposes. It has been added to the electronic bottle. For example, in an electromagnetic balance type feedback loop, a mechanical zero correction device, that is, an analog signal with a minute change as described above, is supplied to a servo motor connected to the spring of the bottle system, so that the system itself is always at zero. A device was inserted to automatically correct the problem. In addition to the above, the digital output corresponding to the minute change at the zero point is simply D/A converted, this analog voltage is fed back to the electric circuit of the balance through an integrator, the input voltage is subtracted, and then the A/D There is a device that always zero-corrects the output by inputting it to a converter. However, as mentioned above, the automatic zero correction device for deviation simply automatically corrects the deviation of the indication temporarily caused by disturbances such as wind or vibration to an apparent zero, so the disturbance disappears immediately after that, and the measurement object However, there was a drawback that the above-mentioned corrected deviation amount turned into a measurement error. Furthermore, in the method of feedback using an integrator, a delay intervenes in the response of the balance balance due to the integral constant of the integrator, a D/A converter and an integrator are required only for zero correction, and mechanical The zero correction device had the disadvantage of being expensive, such as requiring a thermomotor. In the current situation, the field of application of electronic bottles has been greatly expanded due to their great feature that they have many weighing functions and can perform digital processing of values when combined with electronic peripheral equipment. There is a need for a device that can perform measurements immediately after measurement and that can automatically correct minute changes in the zero point caused by various disturbances without the drawbacks mentioned above. This invention was made in view of the above-mentioned current situation.
In order to solve the various problems of changing the zero point indication of the secondary electronic bottle, the zero point (including the zero point after taring)
After confirming that the indicated change has stabilized within a certain allowable fluctuation range, it is determined whether this stable zero point minute change is within a certain allowable minute range, and the minute change within this allowable minute range is determined. By automatically displaying the amount of change as an apparent zero, minute zero point indication changes that can be ignored in terms of weighing accuracy are always displayed as zero, making measurement operations easier and faster and eliminating large weighing errors due to zero correction. The purpose of this invention is to provide a device that can perform highly accurate measurements without the risk of getting caught.

In other words, the capacity value of each bottle is sampled at minute time intervals at fixed intervals, a plurality of these are sequentially stored, and each of the stored value groups is sequentially compared with the sampled value. When a memory value with a variation difference greater than a certain variation tolerance is found in the memory value group, all previous memory values including that memory value are erased, and the sampling and comparison operations are repeated.
When it is determined that there is no stored value in a stored value group that has a variation difference greater than the above-mentioned certain permissible fluctuation range, immediately average each stored value in this stored value group and use this as the weight average value. It determines whether the output calculation means and this weight average are outside or within a certain allowable minute range set in advance, and displays the weight average value that is outside the allowable range as is. Automatically calculates the apparent weight average value within the range. This invention relates to an electronic bottle, characterized in that it is provided with a discrimination display means for displaying as follows. Embodiments of the invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the apparatus of the embodiment. 1 is the object to be measured, 2 is the electromagnetic force balance type husband bottle, and W is the analog signal for detecting the weight of the direct current, which is the mass of 3. A measurement amplifier converts it into a DC voltage analog signal A, which is converted into a digital signal D by an A/D converter 4. In a conventional electronic bottle, this D signal is immediately displayed on a digital display 5 and printed out on a printing device (not shown), but the device of the present invention is equipped with several blocks of electronic circuitry surrounded by dotted lines 6. is a feature. The first feature of this device is that the minute range detection comparator of the block 7 is provided in the front stage of the display 5.
000 digits (digit is the minimum unit of measurement), the width of the bottle, 1, ±3, 5, ±10 digits, etc. are arbitrarily set as the permissible minute range. As an example, if this is set to ±10 digits, it will automatically correct for the zero drift immediately after the power supply is immersed, as well as slight changes in the indicated value due to disturbances such as wind and vibration, and the maximum value that will make it appear zero. This is the allowable range, and in other words, even if a minute change within this range is considered zero, the weighing accuracy is 0.0.
The error is 0.3% and does not pose a practical problem.
Suppose that the minute signal De, which is the output of the A-no-○ converter 4, is input to the comparator 7 through the calculation and data control section 9 through the bypass circuit indicated by the - dotted line 8, then the Df is within ±10 digits. If so, the comparator 7 operates YES, and the above Df is changed to 11 via the automatic correction switch 10.
An apparent zero is displayed on the display 5 by the operation of the tare register 9 and the arithmetic and data control section 9. Further, if the above-mentioned ○f is equal to or more than 10 digits, that is, when the object 1 is placed on the balance 2 and weighed, the comparator 7 operates as NO, that is, it is directly sent to the display 5 and displayed. This is a normal operation when measuring object 2 is placed on the second bottle 1, but if
If the above 10 digits are displayed even though no Therefore, it is necessary to investigate the causes and take appropriate measures, and this is a check to see if the conditions for using the bottles are appropriate. Moreover, if the automatic correction switch 10 is turned OFF, the function of the comparator 7 is stopped and the above ±10
Even minute amounts of less than digits are displayed as is. This is a method used when you want to measure a weighing quantity very precisely under the condition that there are no disturbances, etc., and it is usually set at 10' as shown in the figure. The above is an explanation of the operation of this device using the bypass circuit tentatively shown in FIG. If the above-mentioned vibration subsides and the measured object is weighed, there will be an error of -8 digits in the true weight, which may cause the same drawbacks as the automatic zero correction device of its predecessor.

The second feature of this device, which was provided to eliminate this drawback, is that the main component is a stability detection comparator 20 that inputs Df using a solid line circuit, and a stability detection section that is made up of blocks 21, 22, and 23 added thereto. This is the function of This will be explained using the response graph of the two bottles shown in FIG. The vertical axis D is the output of the A/D converter 4, which is the sensing amount of each bottle, and is the output of the A/D converter 4.
For example, if the allowable minute range set to ±Dfo is
0 digit is indicated as its limit. P' is the variation difference that can be set arbitrarily using the variation tolerance range setting device in Figure 1, 22.
In this example, the value is 4 digits, which is constant no matter what value D is. The machine axis T is the measurement elapsed time sec, and 1 to 1. For example, 1 is 0. This is the number of sampling times N for each $ec. T^ is the time when the power is turned on, TB is the time of the first sampling, and the interval T^-TB is the above-described minute sampling time. Ts. is, for example, 0.8 1.6 3.2 ec set by the averaging stabilization time setting device in FIG. Shows the power of $ec. But this 0. $ec is the maximum time when taking four samples, and as explained below, it varies from 0.6 to 0. It is reduced to this EC (this 0. This EC is a time interval of the comparison cycle when the instructions are stable). The sampling and comparison operations will now be explained with reference to FIGS. 1 and 2. Dr starts from -9, is sequentially sampled from D to D4, and is stored in 23 memory registers. When this D4 is sampled, the 20 comparators immediately start comparing with this as the reference 1, and the variation difference between D4 and D3 is 2.5, and the above variation tolerance range P = 4 or less passes ( 0), but in the next comparison D4 and D2, there is a difference of more than P, resulting in a failure (x). At this point, the comparator erases the stored values of D2, D, from the memory 23, and changes the characteristic C^
Store the above new sampling values D5 and D6 and save D6 and D
5 is (0), D6 and D4 are (0), but D6 and D3 are (x), so sample D7 one more time and use this as a reference point to compare D7 with D6, and D4. and all are (0), so immediately this D7,D
Input B, wide, and D4 to the calculation section 9. Block 9 calculates the arithmetic mean of the above four values.

The time for the above sampling and comparison operation is Ts as shown in the figure.
・=0. Sec, but Ts2 was 0.6ec, totaling 1. During this time, the comparator 20 does not output any output, so the digital display 5 does not display numbers, but blinks unit symbols such as g and 4, several points, etc., to inform the measurer that sampling is continuing. This makes it very convenient for the measurer to use. Returning to FIG. 1, the average value (Df, 24.4) of the towns 7 to D4 calculated in block 9 is input to the minute range detection comparator 7, and the allowable minute range value set therein is input to the minute range detection comparator 7. 1
It is compared with 0, and since it is within that, the above-mentioned 7, 10,
11 and 9, this average value +4.4 is displayed as zero on the display 5, so that the object to be measured 1 can be placed on the second bottle 2 and weighing can be started. Next, we will discuss the power in which the weight value of the husband pin fluctuates by several digits above and below the zero point due to disturbances such as vibrations, as shown in characteristic CB in FIG.

When sampling is done at D8 and D9, D9 is the reference m
When comparing D8, D4, and D3 three times, D9 and D4
is (x), the memory before ○4 is erased, and next is D, . is the reference W and D, . But this is (x), so D immediately samples up to D, 3, D, 4, and with D, 4 as the reference V, the comparison results become all (0) for the first time, ○, . ～Average value of D,4 (Df2ni0
) is output from block 9 to block 7. In the case of the power which fluctuates slightly due to disturbances, etc., the time required for the stable detection section to output the average value is 2.2 ec, which is longer than the above-mentioned power. The above is one thing, and depending on the disturbance conditions that the bottles are subjected to, the degree of measurement accuracy required, etc., for example, the above-mentioned allowable fluctuation range P, the number of samples to be averaged (4,
8.1 needle) can be selected to speed up the process. Reference numeral 12 in FIG. 1 is a tare push button switch, which displays the weight of a container or the like in which an object is to be weighed as zero, and is the same as the conventional device. The operation of the above-mentioned stability detection section is the same as when measuring the object 1 placed on the bottle 2, so that even if the object 1 moves, such as a laboratory animal, it can be efficiently measured. It is. The electronic bottle can be used accurately even under certain conditions, such as no wind or air current, no vibrations from people walking, etc., and the location where it is installed and where changes in room temperature are minimized. After automatically detecting that the zero drift due to slight disturbance conditions that the Shoten pin is likely to receive or the self-heating of the device itself has stabilized, this stable zero drift is automatically corrected as an apparent zero and zero is displayed on the display. It is a requirement of this invention to make it possible.

Therefore, the automatically corrected correction value can be held down to an arbitrary minute value, which is within the allowable range based on the object to be measured and the purpose of measurement, so there is no risk of abnormal errors in the measured value and the desired accuracy can be achieved. Allows for stable weighing.
In addition, the above-mentioned function makes it easier to operate and improves measurement efficiency compared to conventional devices, such as those used to zero-correct animal defecation during continuous weighing of laboratory animals and the like. Since the present invention is constructed as described above, the slave electronic bottle can perform manual zero adjustment each time the zero point is measured due to zero drift after the power is turned on or changes in the zero point indication after erasing the zero point due to unavoidable disturbance conditions. By adding an expensive automatic zero correction and eliminating the possibility of the correction being introduced as a measurement error, the measurement accuracy can be improved by arbitrarily setting each tolerance value suitable for the measurement purpose. Automatically corrects negligible changes in the readings to zero, allows you to start weighing, and even during weighing, a stable weight value is always indicated, making it highly efficient and convenient to use with good accuracy. We were able to provide a device that was

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of an electronic bottle according to an embodiment of the present invention, and FIG. 2 is a graph of the response of the bottle near its zero point, which explains sampling and comparison operations. 1... Weight measurement object, W.A... Weight value (analog signal), D... Weight value (digital signal), Dfo. M... fixed allowable minute range of capacity value, Df... zero point change capacity value, T^-TB... fixed sampling minute time interval (for example 0.$ec), P: Fixed permissible fluctuation range, Df: Average value of a fixed number of sampled values (average amount of weight). 1 figure and 2 hair figures left

Claims (1)

[Claims] 1. Comparison means for sampling the weighing capacity value of the balance at minute time intervals at regular intervals, sequentially storing a plurality of values, and sequentially comparing each of the stored value groups with the sampled value, and When a stored value with a fluctuation difference greater than a set permissible fluctuation range is found in the stored value group, all previous stored values including that stored value are erased, and the sampling and comparison operations are repeated. When it is determined that there is no stored value in a stored value group that has a variation difference greater than the above-mentioned certain permissible fluctuation range, it is an operation that immediately averages each stored value in this stored value group and outputs this as the weight average value. The average value of the capacity is determined whether it is outside or within a certain allowable minute range that is set in advance, and the average value of the capacity that is outside the allowable minute range is displayed as is, and the range is An electronic balance characterized in that it is provided with a discrimination display means for automatically displaying an average weight value within the range as an apparent zero.