SU1434260A1 - Device for measuring total flow rate of liquids and gases - Google Patents

Abstract

The invention relates to instrument making, to devices for measuring the flow of liquids and gases. The aim of the invention is to improve the accuracy of flow measurement. The pulses from the volume flow sensor 1 in the imaging unit 2 are synchronized by the pulses of the reference generator 8, converted into short pulses and counted in the period meter 3, the output of which results in the measurement result as a number equal to N g fg-Tg, where de fjj is the frequency reference generator; T input period. The period counter 5 continuously counts the pulses arriving at its input through key 11 either from generator 8 or multiplier 9, the number of which is compared with N. The result of the comparison controls the operation of the trigger 10 and 14. Gating of the blocks 4 and 6 of the code comparison with inverse generator pulses 8 is performed to eliminate the effect of the transfer process 1 in the counter 5 on their operation. 1 il. WU S (L

Description

U

Od

The invention relates to instrument engineering, in particular to devices for measuring the flow rate of liquids and gases.

The purpose of the invention is to improve the measurement accuracy.

The drawing shows the block diagram of the device.

The device contains a sensor 1 of a volumetric flow rate, a driver 2, a period meter 3, a first block 4 of code comparison, a counter of 5.period, a second block 6 of code comparison, block 7 of a code set, a reference oscillator 8, 15 frequency multiplier 9, the first trigger 10, a key 11, an inverter 12, a block 13 of the multiplication factor set 13, a second trigger 14, a counter 15 and a recorder 16.20

A device for measuring the total flow is as follows.

The input pulses from the volume flow sensor 1 are fed to the input of the puncher 25 of the rafter 2, where they are synchronized by the pulses of the reference generator 8 and converted in duration into a stop equal to the number dialed in block 7, the trigger 14 is outputted by the signal from the output of the second code comparison unit 6 and to the input of counter 5 pulses are received with a frequency f (, K, where K is a coefficient, a smaller unit, and is set using the manual dialing in block 13.

When the number in the counter 5 again becomes greater than the number in the meter 3, the comparison unit 4 is triggered, O appears at the output of the trigger 14, and the output of the trigger 10 10-1. The next impulse enters the counter 15, and then is recorded by the registrar 16. Reset 15 is carried out by the operator's commands (the reset circuits are not shown). If during the counting of pulses in the counter 5 the number in the meter 3 changes upwards, then the counter 5 counts the pulses to this new higher number. If during the counting of pulses in the counter 5 the number in the meter 3 decreases so much that it becomes less than the number already accumulated in the counter 5, then

long pulses t 1/2 TQ, where TC is a code comparison block 4, as a result of the period of the signal of the reference generator 8. DA, the output of the trigger 14 is O,

From the output of the generator 2, the pulses are fed to the input of the meter 3 periods, the output of which forms the result of the measurement as a number

NBX fcTsx, P) fo

Where

gp

in

the frequency of the reference generator period of the input signal. The period counter 5 continuously counts the pulses coming to its input via key 11 either from the output of the reference generator 8 or from the output of the frequency multiplier 9. If the code is equal in the period counter 5 and the code in the Chile period meter 3 when the code in the counter 5 is greater than the code in the period meter 3) the first block is turned on

By comparing the codes and the signal from its output, the triggers 14 and 10 are set to O and 1, respectively. The signal from the output of the trigger 10 sets in O counter 5, and the signal from the output of the trigger 14 connects to the counting input of the counter 5 the generator output

8. Through the half-period by the signal of the generator 8, the trigger 10 is set to the zero position and the period counter

5 counts the generator pulses 8 when the number in the period counter is 5

becomes equal to the number dialed in block 7, trigger 14 by a signal from the output of the second comparator unit codes 6 is set to 1, and pulses with a frequency f (, K, where K is a coefficient less than one and set with manual dialing) arrive at the input of counter 5 block 13.

When the number in the counter 5 again becomes greater than the number in the meter 3, the comparison unit 4 is triggered, O appears at the output of the trigger 14, and the output of the trigger 10 10-1. The next impulse enters the counter 15, and then is recorded by the registrar 16. Reset 15 is carried out by the operator's commands (the reset circuits are not shown). If during the counting of pulses in the counter 5 the number in the meter 3 changes upwards, then the counter 5 counts the pulses to this new higher number. If during the counting of pulses in the counter 5 the number in the meter 3 decreases so much that it becomes less than the number already accumulated in the counter 5, then

five

and at the output of the trigger 10 - 1. The comparing the blocks of inverse pulses of the generator 8 is done in order to eliminate the influence of the transfer process 1 in the counter 5 on their operation.

The output period of the pulse from the output of the trigger 10 is determined by the formula:

 Wih

Nmin, Ngt- NMHH

fo-k

(2)

where is the number dialed in the dialing device, equal to the number of pulses that fall into the period meter 3 with the minimum period of the signal at the input.

Taking into account (1) and what they get

min

,

t +

mmn

 T

min

to

(3)

0

55

Thus, the dependence of the average output period of the device on the input is a linearly increasing function, which is consistent. c with the characteristics of real flow meters in the range of 20-100% of maximum flow. By choosing the appropriate m and k for a specific flow meter, the accuracy of flow measurement can be improved by correcting the dependence of the number of pulses per unit of flow on the capacity.

score

Claims (1)

Invention Formula A device for measuring the total flow of liquids and gases, a co-sensor of volumetric flow, connected through a shaper to a period meter, a reference generator, the output of which is connected to the input of the period meter and the second input of the shaper, the first trigger and counter, the output of which is connected to a recorder that differs In order to improve measurement accuracy, the first and second code comparison blocks, a code dialing block, a key, an inverter, a period counter, a second trigger, a frequency multiplier, and a a set multiplying factor, and the first inputs of the first and second comparing units kosche ten The DSPs are connected to the outputs of the period meter and the code dialing unit, and their second inputs are connected to the output of the period counter, the output of the first code comparison unit is connected to the installation input 1 of the first trigger and the installation input 0 of the second trigger, the installation input 1 of which is connected to the output the second block of code comparison, the output of the reference oscillator is additionally connected to the first input of the frequency multiplier, the second input of which is connected to the block - 15, the set of multiplication factors, input to the O first trigger, the first information key input and through the inverter to the gate inputs of the first and second code comparison blocks, the output of the frequency multiplier is connected to the second key information input, the control input of which is connected to the output of the second trigger, and the output to the counting input of the period counter, while the output of the first trigger is connected to the control input of the period counter and the input of the counter. 20 25