SU892245A1 - Device for measuring pressure - Google Patents

Description

(5). DEVICE FOR MEASURING PRESSURE

one

The invention relates to a measurement technique and can be used to measure pressures in installations for various purposes.

Pressure measuring devices are known using a V-type manometer with sensors for fluid levels in the knees of the manometer Dl.

The closest in technical essence to the invention is a device based on measuring the difference in liquid levels followed by recalculation of the obtained value into pressure, containing two generators with level sensors, a frequency mixer and a recorder in the form of a pulse counter t.l.

In the known device, when it is used to measure pressure, the frequencies of the generators are subtracted, the sensors of which are located on the corresponding tubes of the V-shaped manometer, and the pressure, which is proportional to the difference in the liquid levels in the tubes, relative to each other, is determined from the difference frequency.

However, in this device, the determination of the frequency difference does not take into account the sign of the pressure change. Thus, when the sign of pressure changes relative to the initial one, additional information is needed, in the absence of which the pressure measurement range is reduced. The device can be used only in the presence of an operator to fix the direction of pressure change relative to the initial one or with a known course of pressure change.

In addition, the recorder gives the results in units of frequency, and for 2Q determination of pressure, a subsequent recalculation of the readings of the recorder counter into pressure is necessary, which complicates the processing of measurement results. The aim of the invention is to expand the range of measured pressures and simplify the processing of measurement results. This goal is achieved by having two generators with circuits including linear wave sensors located at the knees of the pressure gauge and connected to the mixer, the output of which is connected to the recorder, to a pressure measuring device containing a / -shaped manometer with a dielectric working fluid. the trigger, the unit for determining the sign of the difference between the frequency of the generators, the shaper of the time interval, the delay element, the setup circuit for the initial values, and the recorder is designed as a reversible counter with two coincidence circuits at the input, the inputs of the generator of the difference of the frequency difference of the generators are connected to the oscillators, and the output is connected to the trigger input, the output of which is connected to the control input of the reversible counter, the time interval generator is connected to the clock generator through a delay element which is connected to the counter through the initial value setting circuit, the first inputs of the matching circuits are connected to the mixer output, and the second inputs of the matching circuits are connected to the driver; e 1 interval. The drawing shows a block diagram of a device for measuring pressure. A device for measuring pressure contains a V-shaped pressure gauge 1 with a dielectric working fluid, with sensors 2 in the form of long line segments, generators 3 connected to sensors 2, a unit (determining the sign of pressure change and mixer 5 connected to generators 3 trigger 6 connected to the block for determining the sign of the pressure change and the recorder 7, which consists of the circuits 8 and 9, coincidence at the input of the reversible counter 10, the generator of 11 time intervals with the input delay element 12, the clock frequency generator 13, which is unified with the initial value setting circuit 1A, and the display unit 15. In the initial state, the fluid in both legs of the V-shaped manometer.54 4 of 1 is at the same level, which corresponds to the initial pressure value. High-frequency sensors 2, which are segments of long lines included in the quality of the circuits in the circuit of the generators 3, develop a frequency proportional to the level of the liquid.When the liquid levels are equal, the frequencies of the generators are equal and there is no signal at the output of the mixer 5. Before the unit starts operation, the initial 1 x values on the meter are set to the initial pressure value. During the experiment, the liquid in the manometer changes its position relative to the levels established in the tubes at the initial pressure. The frequencies of the generators 3 change proportionally to the changing liquid levels and the frequency is generated at the output of the mixer 5, equal to the frequency difference between the generators 3. In addition, signals from the generators are sent to the pressure change sign unit k, which is based on determining the higher frequency from the generator, corresponding to the left or right tube of the pressure gauge, depending on the selected logic of the device. The signal from the output of block i is fed to a single trigger input, and in case of overpressure over the original trigger, it is thrown and the counter 10 of the recorder 7 counts in the forward code, and when the pressure decreases from the original. C the signal block does not arrive and the counter 10 works for subtraction. The operation of the device is synchronized from the clock generator 13. Before the beginning of each measurement cycle, the pulse from the generator 13 through the circuit 14 sets the initial pressure on the meter, which is previously set in the initial value setting circuit Ik, then sets the trigger 5 to the zero position and starts the driver 11 through the delay element. Shaper 11 generates a time interval that allows the meter to scale to any desired pressure units. Thus, in comparison with the known device, the measurement range is expanded and the processing of measurement results is facilitated.

Claims (1)

Claim A device for measuring pressure containing a V-shaped pressure gauge with a dielectric working fluid, two generators with circuits that include linear wave sensors located in the elbows of the pressure gauge and connected to a mixer, the output of which is connected to the recorder, which differs in that, in order to expand the range of measured pressures and simplify the processing of measurement results, a trigger, a unit for determining the sign of the difference in the frequencies of the generators, a shaper of the time interval, a delay element, a setup circuit are introduced into it new initial values, and the recorder is made in the form of a reversible counter with two matching schemes at the input, and 892245 * the inputs of the unit for determining the sign of the frequency difference of the generators are connected to the generators, and the output is connected to the input of the trigger, the output of which is connected 5 to the control mode operation input. a reverse counter, the time interval shaper is connected to the clock generator via a delay element, which is connected to 10 counters via the initial value setting circuit, the first inputs of the matching circuits are connected to the mixer output, and the second inputs of the matching circuits are connected to the time interval shaper.