Performance of transducers

Transducers are devices which on subjection to some physical change, experience a related change. Some parameters used to assess the performance of a transducer are accuracy, sensitivity, range and span, error, stability, reproducibility, resolution, dead band and output impedance. Accuracy which is expressed as a percentage of the full range output or full-scale deflection is the extent to which the value indicated by a measurement system might be wrong. The sensitivity gives quantitative relationship between input and output. The transducer range gives an idea about the limits between which the input can vary. The span is the difference between maximum and minimum input. The difference between measured value and true value gives error. The main two errors in a transducer are hysteresis error and non-linearity error. The stability of a transducer signifies its ability to give the same output when used to measure a constant input over a period of time. Reproducibility is the ability of a transducer to yield the same output for repeated applications with the same input value. The resolution implies the smallest change in the input value which produces smallest observable change in output. The dead band of a transducer is the range of input values for which there is no output.