Pressure Gauge Performance Characteristics

Pressure Gauge is normally referred to as a self-contained indicator which can transform the detected process pressure into the mechanical motion of a pointer. A pressure transducer might join the sensor element of a gauge with a mechanical-to-electrical or mechanical-to-pneumatic converter and a power supply.

Accuracy: “It refers to the degree of conformity of the measured value to an accepted standard. It is usually expressed as a percentage of either the full scale or of the actual reading of the instrument. In case of percent-full-scale devices, error increases as the absolute value of the measurement drops”.

Repeatability: It refers to the closeness of agreement among a number of successive measurements of the same variable.

Linearity: It is a measure of how appropriate the output of transducer increases linearly with increasing pressure.

Hysteresis error: This characteristic explains the phenomenon according to which the same process pressure results in different output signals depending upon whether the pressure is approached from a lower or higher pressure.

Sensitivity: It determines the amount of variation that occurs in the output voltage as and when the input voltage varies, keeping in view that the measured pressure and the rated pressure of the transducer remains constant.

In industrial applications, good repeatability is considered more significant as compared to absolute accuracy. For pressure variations over a wide range, transducers with good linearity and low hysteresis are the ideal choice.