Type determination based on measuring object and environment
A sensor with certain principle should be first considered for specific measurement, which requires the analysis of many factors to determine. Because the sensors with multiple principles are available for selection even measuring the same physical quantity. People who select a more appropriate sensor with certain principle need to consider the following concrete factors in accordance with the measured features and the service conditions of sensor: range size; requirements of measured position for sensor volume; contact or non-contact measurement; lead approach for signals, cable or non-contact measurement; sensor origin, price and self-development.
What type of sensor can be determined to use after considering the above issues and then the specific performance indicators of sensor should be considered.
Sensitivity selection
Typically, the higher the sensitivity of sensor is, the better the sensor is expected within the linear range of sensor. Because the values of output signals corresponding to the change of measured object are relatively large only due to higher sensitivity, which is favorable for signal processing. It should be noted that the external noises independent of measured object would easily interfuse and be amplified by amplification system thus affecting the measurement accuracy due to the higher sensitivity of sensor. Therefore, the higher SNR should be required for the sensor itself to reduce the interference signals from the outside.
The sensitivity of sensor is directional. When the measured is one-directional but requires higher directivity, the sensor with lower sensitivity in other direction should be selected; If the measured is multi-dimensional, the sensor with the lowest cross sensitivity should be selected.

Frequency response characteristic

The frequency response characteristics of sensor determine the measured frequency range. Nondistortion must be remained in the sensor within the allowable frequency range. In fact, there is always some delay for the response of sensor but the delay is expected to be shorter as possible.
The higher the frequency response of sensor is, the wider the frequency range of measurable signals is.
In the dynamic measurement, the frequency response characteristics should be based on the characteristics of signals (steady state, transient state, random, etc.) in order to avoid excessive errors.
Linear range
Linear range of sensor is the range in which the output is proportional to the input. In theory, the sensitivity remains constant in this range. The wider the linear range of sensor is, the greater the range is and certain accuracy of measurement can be guaranteed. When selecting a sensor, we should first check the sensor whether its range meets the requirements after its type is determined.
In practice, any sensor cannot guarantee absolute linearity and the linearity is relative. When the required measurement accuracy is lower, the sensor with smaller non-linear errors can be approximately regarded as linear within a certain range, which will bring great convenience to the measurement.
Stability
The ability for sensor to maintain stable performance is called stability after it is used for a period of time. The main factor affecting the long-term stability of sensor is the service environment of sensor besides the structure itself. Therefore, the sensor must have a strong environmental adaptability for its excellent stability.
The service environment of sensor should be investigated before selection and an appropriate sensor should be selected according to the specific service environment or appropriate measures should be taken to reduce the environmental impact.
The stability of sensor has quantitative indicators. The indicators of its stability should be re-calibrated to determine whether the performance of sensor has been changed after its lifetime is exceeded or before use.
In some occasions when the sensor is required for long-term use but cannot be easily replaced or calibrated, the selected sensor requires more strict stability and is able to withstand long-playing operation.

Accuracy
Accuracy is an important performance indicator of sensor. It is the important link related to the measurement accuracy of entire measurement system. The higher the accuracy of sensor is, the more expensive its price is. Therefore, only if the accuracy of sensor meets the accuracy requirements of entire measurement system, it is not necessary to select a sensor with too high accuracy. So Atlas air compressor parts of cheaper and simpler sensor can be selected among many sensors which meet the same measurement purpose.
If the measurement purpose is to carry on qualitative analysis, the sensor with high repeated accuracy should be selected and that with high accuracy of absolute measurement is inappropriate to use; If the measurement purpose is for quantitative analysis to obtain accurate measurements, the sensors whose accuracy level can meet the requirements should be selected.
For some special occasions, you need design and manufacture the sensors by yourselves since appropriate sensors cannot be found. The homemade sensors should meet the operating requirements.