SU697818A1 - Device for measuring the trim of float-type instruments at balancing - Google Patents

Description

(54) DEVICE FOR MEASURING A DIFFERENT WHEN BALANCING A FLOOR DEVICE

The invention relates to the field of instrumentation technology and is intended to monitor and measure trim of float devices. There are devices for measuring the trim of float devices, including spring or lever scales, or determining the trim by directly hanging test weights on the float and selecting them 1. However, when hanging loads on the float, it is difficult to avoid dynamic loads. This disadvantage is eliminated by equalizing the float by changing the temperature of the fluid supported by it and then calculating the trim with regard to the viscosity coefficients and temperatures of the fluid and the float 2. These devices have a relatively low measurement accuracy due to inaccuracy and discontinuity of the goods, environment and float (before measurement and at the time of measurement). The best result for this is a device for balancing and measuring trim of float devices 5, in which, to improve the accuracy of determining the trim and imbalance of the float, the ring magnetic circuit with the solenoid: 1 :, located on equal distances from pole pieces with an adjustable magnetic field, with one pole piece of the magnetic circuit connected through a gearbox with an electric motor. However, this device has a relatively low measurement accuracy due to the occurrence of solenoid scattering fluxes and the effect on the measurement of external electromagnetic fields. The aim of the invention is to improve the accuracy of the trim measurement. This goal is achieved by the fact that in a device for measuring trim when balancing float devices containing a base, a float-type sensitive element, a measuring mechanism and a recording device, the measuring mechanism is designed as a movement-sensitive piezoquartz element, one of the excitation electrodes of which is a metallized surface. pplavka - frame, and the other - a metal electrode of variable thickness, deposited on a piezoquartz element, both electrodes connected to a piezoelectric oscillation amplifier introduced into the device, the output of which is connected to the input of a recording device.

The drawing shows a schematic diagram of the proposed device.

On the base 1 in the housing 2 in the liquid (not shown), a float is mounted — frame 3. Outside the liquid, there are piezoquartz elements 4 above which the exciting electrodes 5 are located, with some clearance from their main faces, mechanically connected to the float - frame 3, and electrically connected to the electronic exciter 6. Float - frame 3 is attached to the body using torsions 7 that hold the frame in a horizontal position. On the opposite main face of piezoquartz elements deposited electrode 8 of variable thickness, which is also connected to the electronic exciter 6. The outputs of the electronic exciters are connected to the input of the regulating device 9, calibrated in trim values.

The operation of the proposed device is based on a change in the position of the float, which is measured from the initial zero position.

An exemplary float device having a zero trim is placed in frame 3. In this case, the float frame has an initial zero position. Exciting electrodes 5 also occupy (relative to piezoquartz elements 4) the zero position, which corresponds to a certain value (taken as zero) of the frequency of the piezoelectric oscillations. The recording device 9 registers the electrical signals from the output of the electronic exciters 6, the frequencies of which, as well as their differences, correspond to the zero trim value, in units of which the device 9 is graduated.

Since piezoquartz elements have a high quality and linearity of the conversion characteristic, high stability and accuracy of trim measurement (0.1 tons 0.01%) is ensured.

The output of the trimmer is the electrical signal frequency, which allows it to interface with digital computing and control masses for analyzing and automating production processes.

Thus, the proposed device compared with the same has the following advantages:

-improve measurement accuracy by using a piezoquartz transducer with high Q, stability and linearity

conversion factor;

- provision of remote measurement of the trim value due to removal of the converter from the fluid for a certain distance;

- ensuring the possibility of automating the measurement process using digital control masks due to the presence of a frequency output signal;

-small dimensions and weight due to the use of microminiature piezoelectric elements and

electronic circuits;

- ensuring that the device can be switched on according to the differential scheme, which reduces the influence of external mechanical and electromagnetic interference.

Claims (3)

1. USSR Author's Certificate No. 177127, cl. G 01 M 1/12, 1965. 2. USSR author's certificate number 161554, cl. G 01 M 1/12, 1964. 3. USSR author's certificate No. 147831, cl. G 01 M 1/12, 1962 (prototype). /