6 Core Sensor Selection Factors: Explained in One Article

6 Key Factors for Sensor Selection: Type, Sensitivity, Stability…

Modern sensors vary greatly in principle and structure. How to reasonably select sensors according to the specific purpose of measurement, the measurement object, and the measurement environment, is the first problem to be solved in measurement. When the sensor is determined, the matching measurement method and measurement equipment can also be determined. The success or failure of the measurement results, to a large extent, depends on whether the sensor selection is reasonable.

01  Starting with Sensor Principle

Based on the measurement object and the measurement environment, to determine the type of sensor for a specific measurement, the first consideration is the principle of the sensor to be used. This requires analyzing a number of factors before making a decision. Because, even for measuring the same physical quantity, there are various principles of sensors that can be selected. To determine which principle of the sensor is more appropriate, it is necessary to consider the following specific issues based on the characteristics of the sensor and the conditions of use: the range size; the volume requirements of the sensor at the measured position; whether the measurement is contact or non-contact; the source of the sensor, whether domestic or imported, affordable, or self-developed. After considering the above issues, one will be able to determine what type of sensor to use, and then consider the specific performance indicators of the sensor.

02  Choice of Sensitivity

Usually, within the linear range of the sensor, it is desirable for the sensor's sensitivity to be as high as possible. Because only when the sensitivity is high, and the change in the measured value corresponds to a relatively large change in the output signal, is it conducive to signal processing. However, it should be noted that a high sensor sensitivity also makes it easy for unrelated external noise to mix in, which will also be amplified by the amplification system, affecting measurement accuracy. Therefore, the sensor itself should have a high signal-to-noise ratio to minimize the introduction of interference signals from the outside world. The sensitivity of the sensor is directional. When the measurement is of a unidirectional quantity with high directional requirements, then the sensor should have a small sensitivity in the other direction; if the measurement is of a multi-dimensional vector, then the sensor is required to have a sensitivity that is as small as possible.

03  Response Characteristics (Response Time)

The frequency response characteristics of the sensor determine the frequency range to be measured. It must be maintained within the allowable frequency range without distortion of the measurement conditions. In fact, there is always a delay in the response of the sensor - a certain amount of delay. It is desirable for the delay time to be as short as possible. A high sensor frequency response allows for a wider measurable signal frequency range. However, due to the impact of structural characteristics, the mechanical system's inertia is large, so the lower the frequency of the sensor, the lower the measurable signal frequency. In dynamic measurements, the response characteristics should be based on the characteristics of the signal (steady state, transient, random, etc.) to avoid producing overshoot errors.