SU991141A1 - Device for measuring displacements and temperature - Google Patents

Description

(54) DEVICE FOR MEASUREMENT OF DISPLACEMENTS AND TEMPERATURES

one

The invention relates to a measuring technique and can be used in devices and information-measuring systems intended for the joint measurement of linear displacements and temperature.

A device for measuring on the basis of inductive displacement transducers is known, in which there is an additive test formation unit 1).

The drawbacks of the device are substantial structural redundancy and, as a result, low reliability.

Closest to the invention in its technical essence is a combined device for measuring displacements and temperatures, comprising a housing housed therein. an inductance coil with a tap from half of the coils, a movable core inside it, which is connected to the object being monitored during the measurement, a & 1 sensitive element connected to the terminals of the inductance and connected in series to the measuring and computing units and the control unit connected to them. In addition to this inductance coil with a movable core placed inside it, there are two additional inductance coils, the movable cores of which are installed with a predetermined reference displacement relative to the first core. The terminals of these coils are connected to the input.

10 measuring unit through the switch. The thermosensitive element of the device is made in the form of thermosensitive cores of additional inductors, which have linear expansion coefficients of opposite sign 2.

The disadvantages of the known device are low accuracy, due to the possible nondentality of the measuring coils.

20 inductance, and low reliability due to its structural complexity.

Claims (2)

The purpose of the invention is to improve the accuracy and reliability of the device. This goal is achieved by the fact that the device for measuring displacements and temperatures is equipped with a heating-cooling unit for a thermo-sensitive element made in the form of a bimetallic plate that is perpendicular to the direction of movement of the core, one end of the plate is fixed to the housing, and the other is hinged to the inductor, mounted with a possibility of displacement in the direction of movement of the core, and is located between two stops mounted on the housing. The drawing shows the structural construction of a device for measuring displacement and temperature. It contains an inductance coil 1 with terminals 2-4, with terminal 3 being a tap from half of its turns. The movable ferromagic core 5 is located inside the inductance coil 1. In the housing 6 there is a left support 7 and a right support 8, between which the free end of the bimetallic plate located perpendicular to the direction of movement X of core 5 is located. The opposite end of the bimetallic plate 9 is fixed rigidly on the case 6 and the other is hingedly movable with the moving one in the direction X inductance coil 1. Associated with the bimetallic plate 9 is a heating-cooling unit 10. To pins 2-4 of coil 1 inductance is connected meter-. And, and to its output, calculating unit 12. Control unit 13, connecting SO4041 to heating-cooling unit 10, measuring unit 11 and computing unit 12. The full cycle of the device operation consists of six consecutive cycles. In the first cycle, using the control unit 13, the terminals 2 and 3 of coil 1 are connected to the input of measuring unit 1. The electrical signal NI at the output of measuring unit 11 is proportional to the value X0 and X + e where X0 is the initial position of the core 5, symmetrical with respect to the coil sections 1 inductance with pins 2 and 3 and 3-4; X - movement of the measurement object (not shown); - the displacement of the inductance coil 1 from the initial position of the bimetallic plate 9, when it is located on the left support 7. The value -j. proportional to the measured temperature T: e - oLCT-Tw, iv,), (O where c is the temperature sensitivity of the bimetallic plate 9; T. is the minimum measured temperature corresponding to the position of the plate 9 on the left support 7. In the second clock cycle The input of the measuring unit 11 is connected via the control unit 13 to the terminals 3 and 4 of the coils 1. The electrical signal Na at the output of the measuring unit is pro-propponded to the value of AO-1- 4. The values of N i and N2 are entered into the memory of the computing unit 12, after which from the output of the control unit 13, a control signal is applied to The heating-cooling unit 10 and the bimetallic plate 9, which ensures its cooling to the temperature T Ynw. Bending, the bimetallic plate displaces the inductance coil 1 up to the stop 7. This position of the coil takes the third and fourth measurement cycles, during which the input of the measuring unit 11 is connected respectively, pins 2-3 and 3-4. The electrical signals N3 and; N4 at the output of the measuring unit are proportional to the values (Xo + X) and (Xr-X), respectively. These signals are also stored in the memory of the computing unit 12. At the end of the fourth cycle, the control unit 13 turns on the heating-cooling unit 10, which provides heating of the bimetallic plate 9 to the temperature T / T ,. Bending in the opposite direction, the bimetallic plate displaces the inductance coil up to the stop 8. In this position of coil 1, the fifth and sixth measurement cycles are performed, during which terminals 2-3 and 3-4 of this coil are alternately connected to the input of the measuring unit 11. Electrical signals N; and N at the output of the measuring unit are proportional, opal, respectively, to the quantities: (Xo + X + + D) and (Xo-X-A), where D is the distance between the stops. These signals are also stored in the memory of the computing unit 12. The actual device conversion function is approximated by a parabolic relationship. As a result, at the end of these six cycles, the measurement unit 12 solves the following system of equations: a txo x-e-d) н n-d) f C -Q (. (HQ -) (- t) C) (() % bCXoi-x -A) fC i Vlg ct () - -bCXo -X D) -C | Me (Wo-x-dL (Xo-X-d) 4c. In this case, the values NI-N N3-N4 are calculated; Nj-Nfi-no) for the results of 3-6 cycles, the measured displacement x is calculated: (i y The T value is determined by taking into account the formula (1) according to the results of 1-6 cycles: for CHY- | -Ha (A-g CN5-WtV (M, -M4) cl wtM The values of the constants A, a, Tuu are stored in the memory cells of the computational unit 12. Thus, in the proposed device with the help of a single measuring channel, both displacement and temperature are measured. As can be seen from expressions (2) and (3), the measurement results of these parameters are not affected by unstable Offsets of the real conversion function of the device, which ensures its high accuracy, simplifies the design of the device and increases its reliability. Invention A device for measuring displacement and temperature, comprising a housing, is placed ///// 7 7/777/7 / y / Y /// YA f f l Kri / 77Z yzzzzzzz ZZZZZZZZ t 77777. { // 16 in it there is an inductance coil with a tap from half of the coils, a moving core inside it, connected to the object being monitored during the measurement, a temperature-sensitive element connected to the terminals of the inductance and connected in series to the measuring and computing units and the block connected to them management, in order to increase. accuracy and reliability, it is equipped with a heating-cooling unit for a temperature-sensitive element made in the form of a bimetallic plate, which is perpendicular to the direction of movement of the core, one end of the plate is fixed to the housing, and the other is hinged to the inductors installed with a possibility of displacement in the direction core movement, and is located between two stops, made on the body. Sources of information taken into account during the examination 1. USSR author's certificate No. 462061, cl. G 01 B 7/00, 1980. 2. USSR author's certificate for application number 2944089/28, cl. G 01 B 7/00, 1980 (prototype).