SU54353A1 - Manometer - Google Patents

Description

At present, three types of pressure gauges are used to measure high pressures: Bourdon pressure gauges, resistance pressure gauges and weight gauges.

Bourdon pressure gauges, which have very convenient qualities in terms of handling them, have relatively little accuracy. In addition, the manufacture of such pressure gauges at pressures above 1000 atm. presents a number of great difficulties.

Resistance manometers, based on the change in metal wire resistance under pressure, are used to measure ultrahigh pressures. A relatively expensive apparatus is required for their manufacture (for example, a bridge for measuring electrical resistance). In addition, such gauges are very difficult to operate.

Weighing or so-called absolute pressure gauges are extremely difficult to manufacture and expensive.

The proposed type of pressure gauge, unlike the existing types, is simple to manufacture and operate, is cheap and can be used both for measuring low pressures and

high up to 10,000 atm. with any accuracy.

In the proposed manometer, the pressure change is determined by the change in the volume of the hollow body, the cavity of which is subjected to pressure and which is enclosed by the second hollow body connected to the capillary.

A liquid is introduced into the gap between the hollow bodies; according to the height of the liquid column in the capillary, when the first body expands, the measured pressure is judged.

The drawing shows a schematic section of the proposed pressure gauge.

The pressure gauge consists of a metal hollow body 3, fitted with a nipple seal 1 and covered by an outer hollow body 4 connected to a capillary 7 and pressure plates 8.

The hollow body 3 can be made, depending on the application of the pressure gauge, from carbon or special steel, single-layer or multi-layer. The dimensions of the body 3 can vary, depending on the accuracy required, from very small to significant.

To reduce the volume of the manometer, insert 2 may be inserted into the internal cavity of the body 5. The gap between the insert and the internal wall of the body 5 can be made to any degree small, which does not affect the accuracy of the measurement.

The sealing of the open end of the body 5 can be carried out either with the help of flanges or with the help of nipples or other known methods.

The outer cylinder — the enclosing hollow body 4 is made of metal, glass, or other dense materials. With the lower part, the body 4 is fastened either by thread or by any other means to the body 3 of the pressure gauge. A capillary tube 7 and a valve 6 are connected to the upper part of the body 4, which serves to fill the pressure gauge with liquid. Between the outer surface of the body 5 and the inner surface of the outer body, a small gap 12 of 0.05 mm or more is made, which is filled with liquid.

Mercury, colored organic liquid products, water, etc. can be used as liquids.

The capillary tube can be in communication with air or zap. The diameter of the capillary can vary widely, depending on the required measurement accuracy.

The principle of the manometer is based on an increase in the volume of the metal hollow body 3 under the influence of internal pressure and the ejection of this fluid from the gap 12 between the body 5 and the body 4 in the capillary 7. Judging the height of the liquid column in the capillary 7 pressure.

A pressure gauge can be used to measure a wide range of pressures (for example, from 1 to

10 000 atm.), And for measuring narrow intervals (for example, from 1000 to 2000 atm., From 2000 to 3000 atm., Etc.). To do this, it is only necessary to make minor design changes in the device of the capillary or change the amount of fluid in the system.

By changing the diameter of the capillary or the size of the body 3 manometer, you can build a manometer of any accuracy.

The pressure gauge can be used under laboratory conditions to measure pressures in a wide or narrow pressure range with a given (high or low) accuracy and under production conditions to measure high (above 1000 atm.) Pressures.

To eliminate the effect of temperature, the pressure gauge can be thermostatted or placed in a liquid bath 5, the temperature of which must be accurately measured. When the pressure is read in the latter case, it is necessary to make corrections for the change in the position of the meniscus of the liquid in the capillary depending on the temperature. In order to facilitate the introduction of these amendments, a thermometric scale 10 may be provided for in the design. A qualitative test of a pressure gauge based on the described principle, carried out in laboratory conditions, has shown good results.

The subject matter of the invention.

A manometer, characterized by the use of a hollow body 5, covered by a second hollow body 4, into which a liquid is introduced into the gap 12 between which is connected to the capillary 7, with a view to applying the pressure in the body 3 to the height of the liquid column in the capillary 7 pressure.