SU900142A2 - Device for investigating unstable temperature effects on pressure pickups - Google Patents

Description

(54) DEVICE FOR INVESTIGATING THE INFLUENCE OF UNSTEADY TEMPERATURES ON THE PRESSURE SENSOR

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The invention relates to a measurement technique, in particular, to means of testing pressure sensors, and can be used in determining the components of the temperature error of pressure sensors in conditions of unsteady heat flow.

According to the main author. St. No. 524987, a device is known for studying the effect of non-stationary temperatures on a pressure sensor, comprising a metal bath, a sensor displacement mechanism, and recording equipment connected to the sensor. In the device, the sensor displacement mechanism is made in the form of a rod with a drive and electric control contacts located on it, included in the program control circuit of the unit, and the bath with the molten metal is equipped with a heat shield with a scraper in contact with the surface of the melt. The drive for shifting this tap from the bath is synchronized with the drive for moving the sensor and the switch of the recording apparatus by means of the indicated control unit.

The device allows you to simulate a transient thermal effect on the pressure sensor while simultaneously registering its electrical output signal 1

The disadvantage of this device is the absence of blocks that allow high-precision calibration of sensors at the time of exposure to a non-stationary heat flux, which excludes the possibility of obtaining temperature error components of a non-stationary heat flux component. , Q The purpose of the invention is to improve the accuracy of determining the temperature-fault components of the pressure sensors in a non-stationary heat flux.

The goal is achieved by introducing a source of stabilized pressure and a pneumatic commutator with a drive into the device, while the inputs of the pneumatic commutator channels are interconnected and connected to the stabilized pressure source through the other, and the output of the pneumatic commutator is connected to the inlet pressure sensor under test.

The drawing shows a block diagram of a device for studying the effect of non-stationary temperatures on a pressure sensor.

The device contains a pneumatic circuit breaker I, in the stator body of which channels 2 are made. Even channel numbers are combined and connected to the atmosphere, odd channels through the receiver 3 are connected to a pressure source 4. The control is carried out using an exemplary manometer 5. The rotor of the switch is rotated from the motor b, the mode of operation of which is determined by the control unit 7.

The device includes a mechanism 8 for moving the sensor 9 into the heat flux under study with a predetermined thermal gradient DT, synchronization unit 10, which allows synchronizing the operation of the movement mechanism, the oscilloscope 11 and the thermal camera 12, and the converter-amplifier 13 of the electric signal of the sensor.

The device works as follows.

From the pressure source 4 by means of a crane 14 in the receiver 3, a stabilized pressure Radm is established, corresponding to the upper limit of the sensor 9 operation. The same pressure is established in channels 2 with odd numbers.

Using the control unit 7, the required operating mode of the pneumatic commutation switch 1 is set, which determines the polling period of one point. Pipeline 15 receives periodic pressure steps of the same level into the receiving cavity of the sensor. The electric signal from the sensor under test after amplification and conversion in block 13 is recorded on the tape 16 of the oscilloscope 11. The upper recording level is proportional to the RNON lower level - Ratm. displacement is introduced into the investigated heat flux of the chamber 12, in which a certain temperature gradient A is created. At the same time, the oscilloscope 11 begins to work, on the tape of which a record yvaets information from the sensor is proportional to a known level and the pressure P m

Ratm but distorted due to the error of the sensor in a non-stationary heat flux. In this case, the lower level shift compared to normal conditions is related to the temperature component i of the sensor (zero drift), and the upper write level shift compared to normal conditions is related to the additive and multiplicative components of the error ya + Mp sensor 9 in unsteady flow.

Analyzing the data, you can

construct the dependence of the components of the temperature error of the sensor in the unsteady heat flux at different time intervals.

Claims (1)

Invention Formula A device for investigating the effects of transient temperatures on a pressure sensor according to the author. St. No. 524987, characterized in that, in order to increase the accuracy of determining the temperature error components of the pressure sensors, a stabilized pressure source and a pneumatic commutator with a drive are introduced into it, while the channel inputs of the pneumatic commutator are interconnected and connected to the stabilized pressure source, and the rest the inputs are connected to the environment, and the output of the pneumatic switch is connected to the input of the pressure sensor under test. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 524987, cl. G 01 L 27/00, 1975.