SU935720A1 - Force-measuring resistance strain gauge pickup - Google Patents

Description

This invention relates to instrumentation and may be used in measuring force, mass, pressure, and other mechanical quantities. Known load sensors with glued to the elastic element of the strain gages 1.

The disadvantage of such sensors is the presence of an intermediate link in the transmission of deformation from the elastic element to the strain gages of the film of glue, the inelastic properties of which lead to instability, creep and a limited temperature range of these sensors.

Glue-free strain gauge sensors are also known, in which wire strain gauges are attached to an elastic element without a binder 2..

Due to the absence of a binder, these sensors have a high stability and a higher limit of operating temperatures.

However, the sensitivity of these sensors is insufficient when measuring small forces.

Closest to the invention in its technical essence is a glue-free strain gauge sensor.

containing two parts located at some distance from each other, between which the wire strain gauges are fixed, is the force 5 at the same time elastic element 3.

Due to the absence in this sensor of a special elastic sensitivity of this device is much higher, and it can be used to measure small forces.

However, when measuring body mass placed in a container, a significant part of the measurement range is taken by 15 tare weight, which narrows the working measurement range of the sensor.

The aim of the invention is to expand the working range of the measurement.

The goal is achieved by the fact that the parts, between which the strain gages are fixed, are pressed one against the other by the preload tension force of the strain gages.

FIG. 1 is schematically shown.

25 gauge, general view; in fig. 2 - sensor calibration characteristic.

The sensor consists of a moving part 1 and a fixed part 2.

Claims (3)

A measured load is applied to the moving part 1. Between the parts on the uprights 3, with some tension, the resistors 4 are included in the measuring circuit. The sensor works as follows. The measured force P is applied to the moving part 1, which is pressed against the stationary part 2 by a tension force PQ of the strain gages 4, which is opposite to the force P. When the measured force increases, the resultant pressing force of the parts decreases and becomes equal to zero. With a further increase in P, parts 1 and 2 move away from each other, the strain gauges, 4 change their resistance, which is recorded by known methods. In the range of variation of the force P Pd, the resistance of the resistance strain gages does not change, which cb causes the sensor insensitivity zone. The operating range of the sensor, in which the output signal is proportional to the measured force, is P Pd. Because. The dead band of the sensor is not within its working range of measurement, it is possible to exclude the tare mass when weighing the body weight placed in it, i.e. possibility of extending the working range of the sensor. Deadband can be adjustable-. by changing the initial tension of the strain gauge by known paths, for example, by mutual rewinding of the racks on which the strain gauges are arranged. Claims Intensity strain gauge sensor, containing two parts, between which wire strain gauges are fixed, characterized in that, in order to expand the operating range, the parts are pressed against one another by the preload tension force of the strain gauges. Sources of information taken into account in the examination 1. Patent SYAN 3985025, cl. G 01 L 1/22, published 1976. 2. Author's certificate of the OSSR 679825, cl. G 01 L 1/22, 1978. 3. US patent 39S0984, cl. G 01 L 1/22, published 1976 (prototype). //////////////// ////// //  X Uhhhh / y.