Common Sensor Terminology

Sensors detect specified measured quantities and convert them into usable output signals according to certain rules. They typically consist of a sensing element and a transduction element.

1) The sensing element refers to the part of the sensor that directly responds to the measured quantity.

2) The transduction element converts the measured quantity sensed by the sensing element into an electrical signal suitable for transmission or measurement.

3) When the output is a standardized signal, the device is called a transmitter.

4) Measurement range: the range of measured values within the allowable error limits.

5) Span: the algebraic difference between the upper and lower limits of the measurement range.

6) Accuracy: the degree of agreement between the measurement result and the true value.

7) Repeatability: the degree of agreement among repeated measurements of the same quantity under the same conditions in a short period.

8) Resolution: the smallest change in the measured quantity that the sensor can detect within its specified range.

9) Threshold: the smallest change in the measured quantity that produces a measurable output change at the sensor output.

10) Zero point: the state that makes the absolute output value minimal, for example the balanced state.

11) Excitation: external energy (voltage or current) applied to make the sensor operate normally.

12) Rated excitation: the rated value of excitation voltage or current that can be applied to the sensor under specified conditions.

13) Input impedance: the impedance measured at the sensor input when the output is short-circuited.

14) Output: the electrical quantity produced by the sensor as a function of the applied measured quantity.

15) Output impedance: the impedance measured at the sensor output when the input is short-circuited.

16) Zero output: the sensor output when the applied measured quantity is zero under specified conditions.

17) Hysteresis: the maximum difference in output when the input increases and then decreases within the specified range.

18) Delay: the time lag of output signal change relative to input signal change.

19) Drift: unwanted output changes over time that are unrelated to the measured quantity.

20) Zero drift: change in zero output over a specified time interval under specified conditions.

21) Sensitivity: the ratio of the increment in output to the corresponding increment in input.

22) Sensitivity drift: change in calibration curve slope caused by sensitivity variation.

23) Thermal sensitivity drift: sensitivity drift caused by changes in temperature.

24) Thermal zero drift: zero drift caused by ambient temperature changes.

25) Linearity: the degree to which the calibration curve corresponds to a specified straight line.

26) Nonlinearity: the degree of deviation of the calibration curve from a specified straight line.

27) Long-term stability: the ability of a sensor to remain within allowable error over a specified period.

28) Natural frequency: the free (undamped) oscillation frequency of the sensor without external force.

29) Response: the characteristic of output change relative to changes in the measured quantity.

30) Compensation temperature range: the temperature range over which the sensor maintains span and zero balance within specified limits.

31) Creep: change in output over a specified time while the measured quantity and environmental conditions remain constant.

32) Insulation resistance: unless otherwise specified, the resistance measured between specified insulating parts of the sensor under a specified DC voltage at room temperature.