SU881553A1 - Pressure pickup - Google Patents

Description

(54) PRESSURE SENSOR

I

The invention relates to instrument engineering and can be used to measure pressure.

A pressure sensor is known that contains partially-filled dielectric vessels formed by electrodes made in the form of a rod and two cylinders 11 coaxially located relative to the rod.

A pressure sensor is also known, comprising a housing made in the form of two communicating rectangular-section vessels partially filled with working fluid, made of a dielectric, the two opposite sides of one of the vessels being provided with capacitor plates.

The disadvantages of the known device are the low accuracy and sensitivity of the measurement, due to the fact that as the working fluid can be used only dizdetricheskogo, and also because

As measured by a bridge circuit, only one capacitor is active.

The purpose of the invention is to increase the accuracy and sensitivity of measurement by allowing the use of an electrically conductive liquid as a working fluid.

The goal is achieved by the fact that in the pressure sensor two counter10s place the sides of the second vessel equipped with capacitor plates, and the capacitor plates of both vessels are covered with a dielectric layer.

FIG. 1 shows a diagram of an advanced sensor; in fig. 2 - fold A-A by 4 mg. one; FIG. 3 shows an equivalent wiring diagram when used as a working dielectric fluid; in fig. 4 - then

20, when used as a working conductive liquid.

Claims (2)

The proposed sensor includes a housing made in the form of two communicating vessels 1 and 2 of rectangular cross section, the walls of the vessels being made of insulating material, and the bottom 3 of the case is made of metal and has a terminal a, In the upper part the vessels are provided with fittings 4 and 5 for supplying pressure. On two opposite sides of 6 7 and 8, 9 of each of the vessels, metal plates 10–13 are glued, having corresponding transducers 5, 8, and t E. And a thin layer of dielectric 14–17, for example, epoxy resin, is deposited on these plates. The space inside the vessel is filled with working fluid 18. The connection diagram of the leads with 5, 0, -i and when used as a working dielectric liquid is shown in FIG. 3, and when using a conductive liquid, in FIG. 4. The sensor works as follows. When pressure is applied, the level of the liquid in one of the vessels rises and in the other one drops. the value of h. If a dielectric liquid is used, the plates 10-13 of each of the vessels form capacitors Qj (Fig. 3), while the capacitance of one of the capacitors increases, and the other decreases in proportion to h. By selecting a fluid with different density and dielectric constant, it is possible within certain limits to change the sensitivity and measurement ranges. If an electrically conductive fluid, such as mercury, is used as the working fluid, it forms one common lining of the working capacitors, and plates 10-13 are used as the second plates interconnected according to (Fig. 4), which provides a change in the capacitance of each of the capacitors by D С and by 2 dС in each arm of the measuring half-bridge when the level changes by h. Because. capacitors are used for measurement, all elements of which are in equal parts, and the capacitors themselves are included in different shoulders of the measuring half-bridge; the circuit has the properties of autocompensation when the environmental parameters change — temperature and humidity. The proposed pressure sensor allows, by using different working fluids, to expand the limits of the pressure measurement by 4 times, while increasing the sensitivity by 2 or 4 times for each working fluid and exclude the thermal compensation elements from the measuring circuit. Claims The pressure sensor, comprising a housing made of two partially filled working fluid, communicating rectangular vessels, is made of a dielectric, and two opposite sides of one of the vessels are equipped with capacitor plates, characterized in that, in order to improve the accuracy and sensitivity of measurement due to the possibility of using an electrically conducting fluid as a working fluid, the two opposite sides of the second vessel are provided with capacitor plates, and The capacitors of both vessels are covered with a dielectric layer. Sources of information taken into account in the examination 1. USSR author's certificate number 381933, cl. G 01 L 9/12, 09.11.71. 2. USSR author's certificate number 408180, cl. G 01 L 9/12, 25.05.76 / prototype). S f 15 Vac yxV // I aif (rig.1 ff.yfL ,, .. y (rig: 3 C, t Cr Sz t q .four rig.4