* Question
| Sensor selection technique |
* Answer
| Sensor Selection Techniques Modern sensors vary widely in principle and structure. How to properly select sensors based on specific measurement purposes, measurement objects, and measurement environment is the first problem to be solved when performing a certain amount of measurement.According to the measurement object and the measurement environment to determine the class of the sensor to be carried out – a specific measurement work, first of all to consider the principle of the sensor, which needs to analyze a variety of factors before it can be determined.It is necessary to consider the following specific problems according to the characteristics to be measured and the conditions of use of the sensor: the size of the range; the requirements of the measured position on the sensor volume; the measurement method is contact or non-contact; the signal extraction method, wired or non-contactMeasurement; the source of the sensor, domestic or imported, the price can withstand,Because only the sensitivity is high, the value of the output signal corresponding to the measured change is relatively large, which is beneficial to signal processing.However, it should be noted that the sensitivity of the sensor is high, and external noise that is not related to the measurement is easily mixed in, and is amplified by the amplification system, affecting the measurement accuracy.When the measured is a single vector, and its directivity requirements are high, other sensors with small sensitivity should be selected; if the measured multidimensional vector, the cross sensitivity of the sensor is required to be as small as possible.
The frequency response of the sensor is high, and the measurable signal frequency range is wide. Due to the structural characteristics, the inertia of the mechanical system is large, and the frequency of the signal that can be measured by the low frequency sensor is low.In dynamic measurement, the response characteristics should be based on the characteristics of the signal (steady state, transient, random, etc.) to avoid over-fire error.When selecting a sensor, when the type of sensor is determined, it is first necessary to see if the range is satisfactory.But in reality, any sensor can’t guarantee absolute linearity, and its linearity is relative.In addition to the structure of the sensor itself, the factors affecting the long-term stability of the sensor are mainly the environment in which the sensor is used.Therefore, in order to make the sensor have good stability, the sensor must have strong environmental adaptability.The stability of the sensor has quantitative indicators. After the usage period, it should be recalibrated before use to determine whether the performance of the sensor changes. |
COMMENTS