Selection of sensitivity
In general, within the linear range of the sensor, the higher the sensitivity of the sensor, the better. This is because only when the sensitivity is high, the value of the output signal corresponding to the change to be measured is relatively large, which is conducive to signal processing. However, it should be noted that the sensitivity of the sensor is high, and the external noise that is not related to the measurement is also easy to mix, and will also be amplified by the amplification system, affecting the measurement accuracy. Therefore, it is required that the sensor itself should have a high signal-to-noise ratio to minimize the interference signal introduced from the outside world.
The sensitivity of the sensor is directional. When the measured quantity is a single vector and its directionality is required to be high, the sensor with low sensitivity in other directions should be selected; If the measurement is a multi-dimensional vector, the smaller the cross-sensitivity of the sensor, the better.
Frequency response characteristics
The frequency response characteristics of the sensor determine the frequency range to be measured and must be undistorted within the permissible frequency range. In fact, there is always a certain delay in the response of the sensor, and the shorter the delay time, the better.
The higher the frequency response of the sensor, the wider the frequency range of the signal that can be measured.
In dynamic measurements, the response characteristics should be based on the characteristics of the signal (steady-state, transient, random, etc.) to avoid excessive errors.
Linear range
The linear range of a sensor is the range in which the output is proportional to the input. Theoretically, the sensitivity remains constant within this range. The wider the linear range of the sensor, the greater the measuring range and the measurement accuracy. When selecting a sensor, when the type of sensor is determined, the first thing to see is whether its range meets the requirements.
But in reality, no sensor can guarantee absolute linearity, and its linearity is also relative. When the required measurement accuracy is relatively low, within a certain range, the sensor with small nonlinear error can be approximately regarded as linear, which will bring great convenience to the measurement.
Stability
The ability of a sensor to maintain its performance unchanged over a period of time is known as stability. In addition to the structure of the sensor itself, the factors that affect the long-term stability of the sensor are mainly the environment in which the sensor is used. Therefore, in order for the sensor to have good stability, the sensor must have strong environmental adaptability.
Before selecting a sensor, it is necessary to investigate the environment in which it will be used, and select the appropriate sensor according to the specific environment in which it will be used, or take appropriate measures to reduce the impact of the environment.
There are quantitative indicators for the stability of the sensor, and after the expiration of the service life, it should be recalibrated before use to determine if the performance of the sensor has changed.
In some occasions where the sensor is required to be used for a long time and cannot be easily replaced or calibrated, the stability of the selected sensor is more stringent and can withstand the test for a long time.
Precision
Accuracy is an important performance index of the sensor, and it is an important link related to the measurement accuracy of the whole measurement system. The higher the accuracy of the sensor, the more expensive it is, so the accuracy of the sensor only needs to meet the accuracy requirements of the entire measurement system, and it is not necessary to choose too high. This makes it possible to choose from a wide range of sensors for the same measurement purpose, which are relatively inexpensive and simple sensor Atlas compressor accessories.
If the purpose of measurement is qualitative analysis, it is sufficient to choose a sensor with high repeatability, and it is not appropriate to choose a sensor with high absolute accuracy; If precise measured values are necessary for quantitative analysis, sensors with the required accuracy class are required.
For some special use occasions, if the suitable sensor cannot be selected, the sensor needs to be designed and manufactured by itself. The performance of the self-made sensor should meet the requirements of use.