Method and device for measuring the force wrapper has a bar by determination of its frequency of vibration

摘要

The method of measuring a force s provides a bar 2, 3, which is loaded by the force in the axial direction and is subjected to oscillations of resonance. It is real determine the frequency f of the oscillations of resonance and in which the force by means of the equation (f - c) c, c and c are of the quantities dependent of the properties of the bar 2, 3. The values c and c can be corrected as a function of temperature when the bar 2, 3 is simultaneously people brought to the state of resonance by means of two frequencies (f, f), the ratio between them is formed by two integers. A measuring device comprises a generating oscillations 11 between two nodal points 7, 8, 9, 10 of the bar 2, 3. A sensor 14 is used for determining the frequency real. An excitation circuit 18 controls the excitation frequency by means of the frequency real of the frequency of resonance.