Testing methods for pressure sensors

The production of pressure sensors generally requires systematic testing; After purchasing the pressure sensor, we can perform general routine testing on the pressure sensor and use a multimeter for simple testing. How to use a multimeter for simple testing?

The use of a multimeter to detect pressure sensors can only be used for simple testing, and the test results are only for reference. Multimeter testing can be divided into the following three methods:

Pressure detection: Supply power to the sensor, blow the air guide hole of the pressure sensor with a nozzle, and use the voltage range of a multimeter to detect the voltage change at the output end of the sensor. If the relative sensitivity of the pressure sensor is large, this change will be significant. If there is no change at all, it is necessary to use a pneumatic source to apply pressure.

Bridge circuit detection: mainly detects whether the circuit of the sensor is correct, usually a Wheatstone full bridge circuit, using the ohm range of a multimeter to measure the impedance between the input terminals and the impedance between the output terminals. These two impedances are the input and output impedances of the pressure sensor. If the impedance is infinite and the bridge circuit is disconnected, it indicates that there is a problem with the sensor or the definition of the pin is not correctly determined;

Zero point detection: Use the voltage range of a multimeter to detect the zero point output of the sensor without applying pressure. This output is usually a voltage of mV level. If it exceeds the technical specifications of the sensor, it indicates that the zero deviation of the sensor is out of range;

By using the above three methods, the approximate condition of the pressure sensor can be detected. If precise detection is required, a standard pressure source needs to be used to apply pressure to the sensor, and the sensor needs to be calibrated according to the magnitude of the pressure and the variation of the output signal. And if conditions permit, conduct temperature detection of relevant parameters. In short, the detection of pressure sensors is a responsible task, and a multimeter can perform general testing, which can be applied in many cases. However, if pressure sensors are required to be used in strict environments, systematic testing is necessary.