SU1462128A1 - Pressure transducer - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure pressures with increased accuracy under the conditions of thermal shock. The purpose of the invention is to improve the accuracy under the conditions of thermal shock. When operating under conditions of thermal shock, temperatures on the membrane surface are distributed along functional non-linear dependencies. Due to the construction of circumferential strain gauges 8, 9, 10, 11 in two parts, the arrangement of these parts along circumferences with radii equal to the distance from the center of the membrane to the beginning and end of the radial strain gauges 4, 5, 6, 7, resistances of these parts according to the proposed ratio can compensate for temperature error and thermal shock. 4 il. (L

Description

FC1

ten

20

25

i The invention relates to a measurement technique and can be used to measure pressures under thermal shock conditions.

The purpose of the invention is to improve the accuracy under the conditions of exposure to a thermo-shock.

.In FIG. Figure 1 shows the pressure sensor design; in fig. 2 - section A4A in FIG. one; in fig. 3 - bridges and: 1 measuring scheme; in fig. 4 is a general view of the functional dependence of the temperature distribution.

j The pressure sensor has a housing of 1.15 in the aspirating membrane 2, HJm is made at the same time with fitting 3. On the membrane 4 2, strain gages 4–7 are installed in the radial direction and 8–11 in the circumferential direction.

 All strain gauges are formed in a motor | 5th measuring circuit, represented in FIG. 3. Each shoulder contains two composite strain gauges.

The circumferential strain gauges are made up of two parts, 8 and 9, 10 I1 11, the strain gauges 9 and 10 are mounted on a circle with a radius equal to the distance from the center of the membrane to the beginning of the radial strain gauges 4-7, and the strain gauges 8 and 11 - on a circle with a radius equal to the distance from the center of the membrane to the end of the same radial strain gages.

Radial strain gages also consist of two parts 4 and 5, 6 and 7 in order to ensure the symmetry of the bridge measuring circuit. The sensor works as follows. When the measured pressure is applied 4 through fitting 3 to perceiving 1 Cembrane 2 (Fig. 1), the latter deflects, strain gauges 4-7 experience radial deformation, and strain gauges 8-11 - circumferential.

As a result, a signal appears at the output of the bridge measuring circuit, which is proportional to the pressure being measured.

14621282

from radius f T (r) is non-linear.

By making the circumferential strain gauge components of two parts, the arrangement of these parts in circles with radii equal to the distance from the center of the membrane to the beginning and end of the radial strain gauges, when choosing the ratio of the resistances of these parts in a certain way, it is possible to compensate for the temperature error from thermal - hitting the set temperature.

The ratio of the parts of the circumferential strain gauges is determined from the expression:

R4

kg

T (g,) - T (ri)

- - - - gt / s i

G., g- - g V 1 G - G J G,

T (g) O / G

(one)

thirty

35

40

45

where T (T) is the temperature in points

circles with radius g; T (g) - temperature in points

circle with radius g; g is the radius of the membrane; d is the distance from the center to the beginning of the radial strain gauge;

d is the distance from the center to the end of the radial strain gauge.

The advantage of the proposed pressure sensor is that a change in the ratio of the resistances of the parts of the circumferential resistance strain gages can be obtained. In this case, the change in the resistance ratios can be made either mechanically (for example, by fitting a laser beam) or electrically (by shunting the parts of the strain gauges with constant resistors, which can be placed both inside and outside the sensor body).

Claims (1)

Invention Formula A pressure sensor, comprising a housing with a membrane installed in it, on which the strain gauges are fixed in the circumferential and radial directions, connected to a pavement measuring circuit, characterized in that, in order to improve the accuracy under thermal shock, the thermistors are located in the circumferential direction, made of composite two parts, the first When operating under conditions of thermal shock, at the time of thermal shock, the temperature over the surface of the perceiving membrane is distributed according to the functional dependence, the character of which is presented in general form in FIG. 4. Surface temperature is unevenly distributed over the radius. Temperature dependence function R4 kg T (g,) - T (ri) - - - - gt / s i G., g- - g V 1 G - G J G, T (g) O / G (one) five 0 five 0 five where T (T) is the temperature in points circles with radius g; T (g) - temperature in points circle with radius g; g is the radius of the membrane; d is the distance from the center to the beginning of the radial strain gauge; d is the distance from the center to the end of the radial strain gauge. The advantage of the proposed pressure sensor is that a change in the ratio of the resistances of the parts of the circumferential resistance strain gages can be obtained. In this case, the change in the resistance ratios can be made either mechanically (for example, by fitting a laser beam) or electrically (by shunting the parts of the strain gauges with constant resistors, which can be placed both inside and outside the sensor body). Invention Formula A pressure sensor, comprising a housing with a membrane installed in it, on which the strain gauges are fixed in the circumferential and radial directions, connected to a pavement measuring circuit, characterized in that, in order to improve the accuracy under thermal shock, the thermistors are located in the circumferential direction, made of composite two parts, the first 14621284 of which are set around the circumference of pa, and the second - around the circumference with a radius with a radius equal to the distance from the mustache equal to the distance from the center of the membrane membrane to the point of the open membrane to the point of the beginning or end of the radial strain gauge-radial tensor resistor. eleven YU 2 Out Ft