Resistance Transducer

Resistance Transducer

 

a potentiometric transducer that converts the measured quantities—such as displacements, geometric dimensions, or angles of rotation—into changes in the electrical resistance of a rheostat. Resistance transducers can be classed as linear or functional and may have translational or rotational displacement of the contact blade. In DC resistance transducers, the output signal y may be a change in current (with transducer connected as a rheostat) or a change in voltage (with transducer connected as a potentiometer).

Linear rheostatic transducers exhibit a constant ratio of the increment of the output signal Δy to the displacement of the contact blade Δx within the measurement range. In the case of functional rheostatic transducers, the relationship y = F(x) is given in advance. For such transducers, the accuracy of measurement (or conversion) depends on a number of factors, including the homogeneity and diameter of the rheostat conductor, the density and uniformity of the conductor winding on the frame, and the ratio of the internal resistance rint of the transducer to the load resistance rload. To ensure a low conversion error, it is necessary that the ratio rint/rload be a minimum. For this purpose, an electronic signal amplifier with a sufficiently large input resistance is often connected to the output of the transducer.

A. V. KOCHEROV