1. Confirm the type of pressure sensor according to the measurement object and measurement environment
In order to carry out a detailed measurement operation, it is necessary to consider the principle of the sensor to be used, which requires the analysis of many elements before it can be confirmed. Because, even if the same physical quantity is measured, there are multiple principles of sensors to choose from, which principle of the sensor is more suitable, it is necessary to consider the following detailed issues according to the characteristics of the measurement and the application conditions of the sensor: the size of the process; The requirements of the measured position for the volume of the sensor; The measurement method is touch type or right or wrong touch type; Signal out method, wired or right or wrong touch measurement; The source of the sensor, domestic or imported, whether the price is acceptable, is still self-developed.
After considering the above questions, it is possible to determine the type of sensor to use, and then consider the detailed function indicators of the sensor.
2. Selection of sensitivity
In general, within the linear scale 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 the sensitivity of the sensor is high, and the external noise that has nothing to do with the measurement is also slightly mixed, which will also be expanded by the expansion system and affect the measurement accuracy. Therefore, it is required that the sensor itself should have a high signal-to-noise ratio to minimize the disturbance signal introduced from the outside world.
The sensitivity of a pressure sensor is directional. When the measured quantity is a one-vector quantity and has high requirements for its directionality, the sensor with small sensitivity in other directions should be selected. If the measured is a multi-dimensional vector, the sensitivity of the sensor is required to be as small as possible.
3. Frequency echo characteristics
The frequency response characteristics of the sensor determine the frequency scale to be measured, and the measurement condition must be adhered to within the allowable frequency scale, in fact, there is always a certain delay in the response of the sensor, and the shorter the delay time, the better. The frequency echo of the sensor is high, and the frequency scale of the measurable signal is wide, and due to the influence of structural characteristics, the inertia of the mechanical system is larger, and the frequency of the measurable signal of the sensor with low frequency is low.
In dynamic measurement, the echoing characteristics of the signal (steady-state, transient, random, etc.) should be based on the error of late overheating.
4. Linear scale
The linear scale of a sensor refers to the size at which the output is proportional to the input. Theoretically, the sensitivity sticks to a fixed value at this scale. The wider the linear scale of the sensor, the greater its measuring range and the guaranteed measurement accuracy. When selecting a sensor, when the variety of the sensor is confirmed, the first thing to see is whether its range meets the requirements.
But in reality, no sensor can guarantee a certain linearity, and linearity is also relative. When the required measurement accuracy is relatively low, within a certain scale, the sensor with small nonlinear error can be approximately regarded as linear, which will bring great convenience to the measurement.
5. Security stability
The ability of a sensor to persist in its function without changing after a period of use is called stability. In addition to the structure of the sensor itself, the main factors that affect the long-term stability of the sensor are the operating environment of the sensor. 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 based on the detailed application environment, or adopt appropriate methods to reduce the impact of the environment.
There are quantitative indicators for the stability of the sensor, and after the service period has passed, it should be calibrated from scratch before operation to confirm whether the function 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 safety requirements of the selected sensor are more stringent and can withstand the test of a long time.
6. Accuracy
Accuracy is an important functional pointer 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 its price is, therefore, the accuracy of the sensor only needs to meet the accuracy requirements of the entire measurement system, and there is no need to choose too high. In this way, it is possible to choose the cheaper and simpler sensor among the many sensors that are satisfactory for the same measurement purpose.
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 accuracy of certain value; If it is necessary to obtain accurate measurement values for the purpose of determining the profile, it is necessary to select a sensor with an accuracy level that satisfies the requirements. For some special applications, if a suitable sensor cannot be selected, it is necessary to design and manufacture the sensor by itself. The function of the self-made sensor should be satisfactory to the application requirements.
It is very important to do a good job in the use and detection of pressure sensors, so we must do the above tests to choose our own suitable pressure sensors.
|
Contact
working hours
