SU1395963A1 - Pressure transducer - Google Patents

Abstract

The invention relates to a measurement technique and can be used as a primary converter in automatic control and regulation systems. The purpose of the invention is to improve the accuracy and raspirovanie measurement range. At the free end of 10 crown 8 there is a device for preventing the resonant buildup of tube 1, made in the form of an additional excitation coil 13, electrically anti-phase excitation coil 12 of the string oscillation 5 connected. , thus, the occurrence of the resonance frequency of the string 5 and the tube 1. 1 Cp f-crystals. 1 il.

Description

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The invention relates to a measurement technique, in particular, to vibration-type pressure sensors, and can be used in a number of technical fields, mainly as a primary converter in automatic control and regulation systems.

The aim of the invention is to improve the accuracy and expand the range of measurements.

The drawing shows one of the possible ibix variants of the proposed pressure sensor.

The pressure sensor consists of a sensing south element in the form of a tube 1 plugged from one side; the internal cavity 2 of which is hydraulically connected to a source of monitored or measured pressure (not shown) via channel 3 in choke 4. The vibrating element is made - 40CTI, in the form of a string 5, is rigidly connected at one end with a holder 6, and the other with a tube 1 through holder 7. Approximately parallel to the string 5, there is a bracket 8, which at one end; with a body part 9. Another - ieii 10 freighter 8 console free ode. In the bracket 8, the pickup coils 11 and the excitation of 12 vibrations of the string 5 are placed. I To increase the accuracy and extend the measurement range, the sensor is equipped with a device to prevent the resonant buildup of tube 1, which in this embodiment is designed as an additional coil 8 mounted on the free end 10 13 of the excitation, the electric powering of which is carried out in the opposite phase with the powering of the coil 12. The device for preventing the resonant buildup of the tube can be accomplished, in the form of a regulator, you its own oscillations varied with emymi shoulder and weight cargo in the form supported on | tube end of the hollow vessel, partially filled with mercury, etc...

The pressure sensor operates as follows.

The controlled pressure enters the internal cavity 2 of the tube 1 and is transformed therein into a force increasing the tension of the string 5, in connection with which the tension in the string increases and the frequency of its natural oscillations excited by the coil 12 increases.

As the controlled pressure increases and the associated change in the frequency of natural oscillations of the string 5, the tube also begins to oscillate due to the rigid connection with the string of its cantilever free end. As the pressure increases, a moment comes when the frequencies of the natural oscillations of the string and the tube become multiple or even equal, which leads to the so-called seizure of the string by the tube, after

The removal coil 11 already fixes the oscillation frequency not of the string, but of a single oscillating tube-string system, which practically does not depend on the pressure in the inner cavity 2 of the tube and has a completely different character. In connection with this,

measurement occurs "failure.

This disadvantage is eliminated due to the presence in the sensor design of a device for preventing the resonant buildup of the tube. In particular, in the described embodiment, by installing an additional excitation coil 13 fed in opposition to the main excitation coil 12, the tube is forced to oscillate, which compensates for the effect of the string on it, thereby reducing the amplitude and resonance of frequencies strings and tubes. This leads to the prevention of the string being caught by the tube, a more accurate fixation of the oscillation frequency of the string, and the expansion of the frequency range of measurements associated with this.

Claims (2)

1. Vibration pressure type-5 pressure sensor, containing a sensitive element in a tube that is gagged on one side, holders, a string fastened in them, and excitation and stripping coils of the string, characterized in that, in order to increase accuracy and broaden the measurement range, Q is equipped with a device to prevent the tube from resonating. 2. A sensor according to claim 1, characterized in that the device for preventing the resonant tube-swinging is made in the form of an additional excitation exciter mounted on the same side of the string and electrically activated anti-phase to the excitation coil of its oscillations.