SU1448216A2 - Weighing apparatus - Google Patents

Abstract

This invention relates to a measurement technique. The aim of the invention is to improve the accuracy of mass measurement by automatically compensating for temperature measurement errors. The initial mass is recorded in the absence of a load by a command from the control panel 8 by transmitting the measured mass code from the load sensor 1 through the analog-to-digital converter (ADC) 2 and the coincidence circuit 3 to the input of the initial mass counter 9. If there is a load, the front-side former 6 generates a pulse of the beginning of the measured mass code, according to which the initial mass is written to the reversing counter 10. The sequential code of the measured mass comes from the output of the ADC 2 through the 4 matching circuit to the subtracting input of the reversing counter 10, pulse the loan of which flies the trigger 11 and thereby introduces the resolution to the circuit 5 of coincidence, after which the remaining number of code pulses is recorded in the reversible counter 10 as a net mass. The falling edge former 7 generates a pulse of the end of the measured code and records the net mass in the indicator device 12 and register 13. If the net weight does not exceed the mass value from the task bus 15 when there is no load, the comparison element 14 generates a command to enter the initial mass before the next measurement . 1 il. (L

Description

m

The invention relates to a measurement technique and can be used in measuring the mass of a material with regard to its initial mass.

The purpose of the invention is to improve the accuracy of mass measurement due to automatic compensation of temperature measurement errors.

The drawing shows the block diagram of the device.

The device contains a force-measuring sensor 1 with an anaphographic converter (ADC) 2, the first, the curtain and the third elements 3-5 coincide with the front 6 and rear 7 front formers (FPF and FZF), control panel (PU) 8, counter 9 the initial mass, the reversible counter 10, the trigger 11, the indicator 12, the register 13, the reference element 14 and the task bus 15.

The information output of the reversible counter 10 is connected to the same input of the register 13, the resolution input of which is connected to the output of the FZF 7. The register 13 output is connected to the first input of the comparison element 14, the second input of which is connected to the task bus 15, and the output of the comparison element 14 connected to the code of the PU 8.

The device works as follows.

An electrical signal, proportional to the applied force, from the output of the sensor 1 is converted by the ADC 2 to a time interval filled with a clock frequency. According to the signal from the control panel 8, through the coincidence element 3, the value of the initial mass is recorded in the counter 9. With the FPF pulse 6, the initial weight value is entered into the reversible counter 10, and the trigger 11 is set in such a position that the coincidence element 4 opens and transmits pulses from the information output of the ADC 2 to the subtracting input of the reversible counter 10.

If the current measured weight is less than the initial one (during unloading), then the number of subtracted pulses will be less than the number of recorded pulses, and the remainder equal to the net weight in the Unload mode will be written to the indicator device 12 in the unloading mode.

If the current measured mass is basic and in load mode.

When all the pulses are subtracted from the reversing counter 10, at its output of the Loan a pulse is formed that flips the trigger 11 into the opposite state, and the element

4 matches is closed and the item

5 matches open. The pulses from the output of the ADC 2 are fed to the summation input of the counter 10. The number of pulses recorded by the pulse of the falling front in the indicator 12 corresponds to the net weight in the load.

Initially, the initial mass is memorized by the signal from the PU 8. Further, in the unloading state, there is information at the output of the reversible counter, equal to the difference between the previously stored initial weight value and the measured current initial weight value. Due to the ambient temperature fluctuations and, accordingly, the change in the temperature measurement error, this difference can reach several units per measurement cycle. Since this temperature measurement error is the same both when measuring the initial weight and when measuring the weight of the load, then in the case of constant correction of the stored value of the initial weight, the weight of the load is measured without temperature error,

A constant automatic correction of the initial weight is carried out as follows.

The code from the output of the counter 10 simultaneously with the recording in the indicator 12 with the same pulse with the FZF 7 is recorded in the register 13 and then compared on the element 11 with the task that is the threshold of temperature error in one measurement cycle, which is set depending on the specific temperature operating conditions.

If the code recorded in register 13 is greater than the task code, then the load mass is measured, and output O of circuit 14 is present. If the code written in register 13,

less task, then a change in the initial mass occurs, and a temperature error of the measurement of the initial mass is recorded in the register (the difference between the measured value of the initial mass in the current and previous cycles). At the same time, at the output of the comparison element 14, there is 1, which opens the coincidence element 3, and in the next measurement cycle a new value of the initial mass is recorded in the counter 9.

Thus, when the sensor 1 acts on the sensor 1, is proportional to the initial mass, the initial mass is continuously recorded in the counter 9.

Claims (1)

Invention Formula Weighing device for auth. No. 1229585, characterized in that, in order to improve the accuracy of mass measurement due to automatic compensation of temperature measurement errors, a register, a comparison circuit and the task bus, the information output of the reversible counter is connected to the register input of the same name, the resolution input of which is connected to the output of the trailing edge former, the register output is connected to the first input of the comparison circuit, the second input of which is connected to the task bus, the output of the comparison circuit is connected to the console input management