The best way to select a sensor?

Sensors are the essential link enabling automatic detection and automatic control. Its existence and development give objects the sense of touch, taste and smell and make objects slowly come to life. Reasonable sensor selection based on the precise measurement purpose, measurement object and measurement environment is the primary problem to be solved when measuring a certain quantity. The success or failure of a measurement result depends largely on whether the alternative of sensor is rational. Let’s take a look at the aspects to think about when selecting a sensor:

1. Determine the kind based on the measurement object and measurement environment

To perform a selected measurement, we must first consider which sensor to make use of, because even when it measures the identical physical quantity, there are sensors with many principles to pick from. Which one is more suitable is dependent upon the measurement. Features and conditions of use are taken under consideration, reminiscent of: the dimensions of the measurement range, the necessities for the measured position within the sensor volume, whether the measurement method is contact or non-contact, the strategy of signal extraction, wired or non-contact measurement, the source of the sensor, domestic or imported, whether the value will be inexpensive or develop it yourself.

After considering the above issues, we are able to determine what sort of sensor to decide on after which take into consideration specific sensor performance metrics.

2. Select sensitivity

Generally speaking, within the linear range of a sensor, it is predicted that the upper the sensor sensitivity, the higher. Because only when the sensitivity is high, the worth of the output signal corresponding to the measured change is comparatively large, which is conducive to signal processing. Nonetheless, it ought to be noted that the sensitivity of the sensor is high, and external noise, which has nothing to do with the measurement, may also be easily mixed in, and may also be amplified by the amplification system, which affects the accuracy of the measurement. Subsequently, it’s required that the sensor itself has the next signal-to-noise ratio and minimizes the interfering signal introduced from the surface world.

The sensitivity of the sensor is directional. When a single vector is measured and the directivity requirements are high, a sensor with less sensitivity in the opposite directions ought to be chosen; if a multidimensional vector is measured, the bottom possible cross-sensitivity of the sensor is required.

3. Frequency response characteristics

The frequency response of the sensor determines the frequency range to be measured and must remain undisturbed inside the permissible frequency range. In point of fact, the sensor response at all times has a relentless delay and it’s hoped that the delay time can be as short as possible. The upper the frequency response of the sensor, the broader the measurable frequency range of the signal.

In dynamic measurement, the response characteristics ought to be based on the signal characteristics (regular state, transient state, random state, etc.) to avoid excessive errors.

4. Linear range

The linear range of a sensor refers back to the range over which the output signal is proportional to the input signal. Theoretically, the sensitivity stays constant inside this range. The broader the linear range of the sensor, the larger the measurement range and a certain measurement accuracy will be guaranteed. When selecting a sensor and determining its type, it is best to first check whether its scope meets the necessities.

But the truth is, no sensor can guarantee absolute linearity, and its linearity can be relative. When the required measurement accuracy is comparatively low inside a certain range, the sensor with smaller nonlinear error will be roughly considered linear, which is able to provide great measurement convenience.

5. Stability

The flexibility of a sensor to take care of its parameters unchanged after a certain period of use is named stability. Along with the design of the sensor itself, aspects that influence the long-term stability of a sensor are primarily the environment through which the sensor is used. Subsequently, for a sensor to have good stability, it should have a high ability to adapt to the environment. Before choosing a sensor, please check its use environment and choose the suitable sensor based on the precise use environment or take appropriate measures to scale back the influence of the environment.

Sensor stability has a quantitative indicator. After the expiration date, it ought to be recalibrated before use to find out whether sensor performance has modified. In some cases, when the sensor must be used for a very long time but can’t be easily replaced or calibrated, the soundness of the chosen sensor is more stringent and must withstand the test for a very long time.

6. Precision

Accuracy is a vital indicator of sensor performance and is a vital link within the measurement accuracy of all the measurement system. The upper the accuracy of the sensor, the dearer it’s. Subsequently, the accuracy of the sensor only needs to fulfill the accuracy requirements of all the measurement system, and it is just not needed to decide on too high. This fashion, cheaper and simpler Atlas air compressor accessories will be chosen from multiple sensors that fulfill the identical measurement purpose.

If the aim of the measurement is qualitative evaluation, select a sensor with high repeatability. A sensor with high absolute value accuracy is just not advisable; whether it is to be a quantitative evaluation and you might want to obtain accurate measurement values, it is best to select a sensor with a level of accuracy that may meet the necessities.

(Summarized by Easyboom)