RU1811598C - Apparatus for calibration testing of differential manometer-flowmeter - Google Patents

Abstract

Usage: for metrological support of laboratory pressure measurements. SUMMARY OF THE INVENTION: an exemplary differential pressure gauge is made cup-shaped, and its inlet and outlet are equipped with atmospheric pressure compensators and shut-off elements. The control pressure gauge is included in the pressure supply line to the calibrated differential pressure gauge. 1 s.p. f-ly, 1 ill.

Description

The invention relates to a technique for measuring pressure and is intended for the calibration of differential pressure flow meters.

An object of the invention is to provide a laboratory facility for checking and repairing flow devices with an extended upper limit of measurement and exclusion. We use mercury in an exemplary cup pressure gauge, i.e. creation of a purely ecological installation.

The drawing shows a diagram of a laboratory installation for checking flow meters.

The laboratory installation for checking flow rate devices contains an exemplary cup pressure gauge 1 with a wide vessel 2, a measuring tube 3 and with an automatic pressure regulator 4, made in the form of a rubber bulb with a cover, a shut-off and regulating valve 5, connecting the tube 3 with pipeline b, the nozzles of which are connected with an exemplary pressure gauge 7, a rotatable differential pressure gauge 8 and a shut-off-regulating valve 9. The measuring tube 10 of the pressure gauge 1 contains an optical readout device 11

and scale 12 and is connected by a pipeline to an automatic pressure regulator 13 similar to regulator 4, and to a shut-off-regulating valve 14 connected to the pipeline of the pressure source.

Installation works as follows.

A rotatable differential pressure gauge 8 complete with a secondary device, a positive valve is connected to the pipeline b and the shut-off-regulating valve 5 is opened. By smoothly opening the shut-off-regulating valve 9 in the pipeline 6, excess pressure is supplied to the calibrated and standard differential pressure gauges. The working fluid from a wide pressure vessel 2 flows into the measuring tube 10. If the meniscus of the working fluid coincides with the scale line 12 on the optical reading device 11 corresponding to 30% of the flow rate, close valve 9. Then, read the indications of model 1 and calibrated 8 differential pressure gauges, analyze them and if the result is positive, i.e. accuracy tolerance / continue verification

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next digitized point. Thus, verification is carried out to the upper limit of measurement of an exemplary cup pressure gauge, which, suppose, is equal to 1000 mm st. filled working fluid. If, according to the calculation, the pressure drop at the next calibration point of the calibrated differential pressure gauge exceeds the upper limit of measurement of a standard cup pressure gauge, i.e. more than 1000 mm the working fluid then proceed as follows. By smoothly opening valve 9, the pressure in the differential pressure gauge 1 is increased until the meniscus of the working fluid in the tube 10 coincides with a pressure of a scale of 12 equal to 1000 mmHg. working fluid and then close the valves 9 and 5. Next, smoothly open the valve 14 and observe the lowering of the meniscus of the column of working fluid. If it coincides with the zero division of the scale 12, close valve 14. The pressure on both sides of the working fluid in the differential pressure gauge 1 and in the pipe 6 is 1000 mm st. working fluid, which can be approximately checked using a standard pressure gauge 7. Thus, the installation is prepared for measuring excess pressure from 1000 to 2000 mm of the height of the working fluid column and further verification is carried out similarly to the above. Thus, alternately increasing and equalizing the pressure on the working fluid from two sides in an exemplary cup differential pressure gauge, we obtain the necessary pressure with an accuracy of 0.3% of the measured pressure drop,

The proposed laboratory apparatus for calibrating flow meters with an exemplary cup differential pressure gauge filled with non-poisonous liquid is simpler, environmentally friendly, relatively accurate in measurement and convenient to measure.

outstanding. In addition, there is no need to build specially equipped premises and benefits for operating personnel are eliminated.

Claims (2)

1. Installation for calibrating a differential pressure flow meter, comprising a gas pressure source, a pressure line through a first locking element connected to a first branch terminating in a hole for connecting a verifiable differential pressure meter, and a second branch connected to the positive input of a standard liquid differential pressure gauge, and a control pressure gauge, characterized in that, in order to expand the range in the direction of pressures exceeding the upper limit scales. exemplary liquid differential pressure gauge, it introduced a second locking element, a back pressure line with a third locking element and first and second atmospheric pressure compensators, an exemplary liquid differential pressure gauge is made cup-shaped, the back pressure line is connected to the negative input of the cup differential pressure gauge and to the pressure line at the point between the pressure source and the first locking element, the second locking element is installed on the positive input of the cup differential pressure gauge, the control pressure gauge is between the first and second locking elements, and the first and second atmospheric pressure compensators communicated with the plus and minus inputs of the cup differential pressure gauge, respectively. . . , .. ... 2. The installation according to claim 1, with the fact that each compensator atmospheric pressure is made in the form of a rubber bulb placed in a mesh cover.