General Performance Terms for Sensors

A device which can feel the prescribed measurement and conver into a usable output signal according to a certain law is called a sensor.

It is usually composed of a sensitive element and a conversion element:

① Sensitive element refers to the sensor can directly sense (or response) the part to be measured. 

② Conversion element refers to the part of sensor which can convert sensitive elements sense (or response) of the measurement into an electrical signal suitable for transmission or measurement.

③ When the output is a prescribed standard signal, it is called a transmitter.

Specifications of sensor have lots of professional terms, the data displayed by these terms, on behalf of performance indicators of the sensors, is an important reference for us to understand whether the sensor to meet the needs of standard use.

Measuring range

The interval determined by the two values of the measurement within the permissible error limit.

Note: The high and low Z values of the measurement are referred to as the“upper limit”and“lower limit”of the measurement range respectively.

Measurement range

The algebraic difference between the upper and lower limits of the measurement range.

Power Consumption

The number of watts of power consumed by a sensor over its operating range when the signal is under stable state conditions.

Electrochemical sensors consume very little power, almost negligible, and are among the lowest power consumption of all available sensors for gas monitoring.

Sensitivity

The difference or ratio between the output (voltage, current, resistance, etc.) of a sensor at a given gas concentration and the output in clean air or reference gas under specified operating conditions.

Resolving rate

The smallest amount of change in the measured quantity that may be detected by a sensor within a specified measuring range.

Linearity

The degree to which a calibration curve agrees with a specified straight line.

Sensitivity Drift

The change in sensitivity of a sensor under specified operating conditions.

Response Time

The time required for the output of a sensor exposed to a step change in gas concentration to change by a specified percentage of the stabilized value (typically 70% or 90%).

Recovery Time

The time interval required for a sensor to resume operation again within its specified tolerance after a specified event (e.g., overload, transient excitation, short-circuit at the output) has ended.

Warm-up time

The time that power needs to be applied to the sensor in advance in order for the sensor to reach a stable operating state.

Long-term stability

The ability of a sensor to maintain constant characteristics over an extended period of time.

Calibration

The process of determining performance of a sensor by recording the corresponding input-output data under specified conditions and by certain test methods.

Reliability

The likelihood (probability) that a sensor will work properly under specified conditions (include a specified period of time, environmental conditions in which the product is located, maintenance conditions, and conditions of use.)

Selectivity

Characterizes the ability of the gas-sensitive element to select the gas to be measured and to suppress interfering gases, which simply refers to the sensor's ability to recognize the type of gas.