Industrial Sensor Selection Method

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Industrial Sensor Selection Method [Copy link]

The emergence of sensors is not surprising. It has brought convenience to people's lives, so the principles and structures of sensors vary greatly. If something is measured by a sensor and it is inaccurate, then there is a problem with the selection of the sensor.

1. Determine the type of sensor based on the measurement object and measurement environment

To carry out a specific measurement, we must first consider which principle of sensor to use, which requires analysis of many factors before we can determine. Because even if we measure the same physical quantity, there are sensors of various principles available for selection. Which principle of sensor is more suitable depends on the characteristics of the measured quantity and the conditions of use of the sensor, including the following specific issues: the size of the measuring range; the requirements of the measured position on the volume of the sensor; whether the measurement method is contact or non-contact; the signal extraction method, wired or non-contact measurement; the source of the sensor, domestic or imported, whether the price is affordable or self-developed.

2. Selection of sensitivity

Usually, within the linear range of the sensor, the higher the sensitivity of the sensor, the better. Because only when the sensitivity is high, the value of the output signal corresponding to the measured change is relatively large, which is conducive to signal processing. However, it should be noted that when the sensitivity of the sensor is high, external noise unrelated to the measured value is also easily mixed in, and will also be amplified by the amplification system, affecting the measurement accuracy. Therefore, the sensor itself should have a high signal-to-noise ratio to minimize the interference signals introduced from the outside world.

3. Frequency response characteristics

The frequency response characteristics of the sensor determine the frequency range of the measured signal, and it must remain undistorted within the allowable frequency range. In fact, the response of the sensor always has a certain delay, and the shorter the delay time, the better. The higher the frequency response of the sensor, the wider the measurable signal frequency range.

4. Linear range

The linear range of a sensor refers to the range in which the output is proportional to the input. Theoretically, within this range, the sensitivity remains constant. The wider the linear range of a sensor, the larger its range is, and a certain measurement accuracy can be guaranteed. When selecting a sensor, after the type of sensor is determined, the first thing to look at is whether its range meets the requirements.
But in fact, no sensor can guarantee absolute linearity, and its linearity is also relative. When the required measurement accuracy is relatively low, within a certain range, a sensor with a smaller nonlinear error can be approximately regarded as linear, which will bring great convenience to the measurement.

5. Stability

The ability of a sensor to maintain its performance after a period of use is called 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 to make the sensor have good stability, the sensor must have strong environmental adaptability.

Before selecting a sensor, you should investigate the environment in which it will be used, and choose a suitable sensor based on the specific environment, or take appropriate measures to reduce the impact of the environment.

6. Accuracy

Accuracy is an important performance indicator of the sensor, and it is an important link related to the measurement accuracy of the entire measurement system. The higher the accuracy of the sensor, the more expensive it is. Therefore, the accuracy of the sensor only needs to meet the accuracy requirements of the entire measurement system, and it does not need to be too high. In this way, you can choose a relatively cheap and simple sensor from many sensors that meet the same measurement purpose.

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