company news about How to Test the Quality of Pressure Sensors

   As a critical component in industrial automation and various monitoring systems, the accurate testing of pressure sensors to determine their performance and condition is an essential step in ensuring the stable operation of the system. This directly impacts the operational efficiency and safety of the entire system.

I. Working Principle of Pressure Sensors

The working principle of pressure sensors is primarily based on physical phenomena such as the piezoelectric effect, strain effect, and capacitive effect. When external pressure is applied to the sensor, the internal sensitive element deforms, leading to changes in physical quantities such as resistance, capacitance, or charge. By measuring these changes, the magnitude of the external pressure can be inferred.

II. Testing Methods

To test the quality of pressure sensors, the following aspects can be considered:

1. Visual Inspection

- Inspect the housing: Ensure the sensor's housing is free from damage or wear to prevent environmental factors from affecting the internal components.

- Inspect the interface: Check that the sensor's interface is intact to ensure the stability of the connection and the quality of signal transmission.

- Inspect the mounting: Ensure the sensor's mounting is secure to prevent measurement errors due to instability.

2. Pressure Testing

- Power supply and connection: Power the sensor and connect its output to a multi-meter to detect changes in output voltage.

- Blow test: Gently blow into the sensor's air hole and observe the voltage change on the multi-meter. A sensitive sensor should show a noticeable change. If there is no change, a pneumatic source may be needed for pressure testing.

- Standard pressure source test: If possible, use a standard pressure source to apply pressure to the sensor. Record the output voltage at different pressures and plot the pressure-voltage curve. The sensor's performance can be judged by comparing the linearity and repeatability of the curve.

3. Zero-Point Detection

- No-pressure detection: Place the sensor in a no-pressure state and use a multi-meter to detect its zero output, typically in millivolt. If the zero output exceeds the sensor's technical specifications, the sensor may require calibration or replacement.

4. Bridge Detection (Circuit Testing)

- Use the ohmmeter: Measure the impedance between the sensor's input terminals and output terminals using the ohmmeter. These impedances represent the sensor's input and output impedance.

- Determine bridge status: If the impedance is infinite, the bridge may be broken, indicating a potential issue with the sensor or incorrect pin definitions. Further inspection and repair may be necessary.

5. Electrical Performance Testing

- Zero-point drift detection: Place the sensor under standard atmospheric pressure and record its output voltage in the zero-pressure state. Compare this value with the zero-point drift value in the sensor's technical specifications to determine if drift is occurring.

- Full-scale test: Place the sensor under maximum pressure and record its output voltage. Compare this value with the full-scale value in the sensor's technical specifications to determine if overload is occurring.

- Sensitivity test: Apply a small pressure change to the sensor and record the change in output voltage. Calculate the sensitivity (change in output voltage/change in pressure) to determine if the sensor's sensitivity meets requirements.

- Linearity test: Apply a series of different pressures within the sensor's measurement range and record the corresponding output voltages. Plot the pressure-voltage curve and calculate the linearity error (maximum deviation/full-scale value) to determine if the sensor's linearity is acceptable.

III. Precautions During Testing

- Safety first: Ensure the safety of the testing environment and equipment to prevent accidents due to improper operation.

- Correct connection: Ensure the correct and secure connection of the sensor and testing equipment to prevent testing errors due to poor connections.

- Standard equipment: Use standard pressure sources and other standard equipment when possible to improve the accuracy and reliability of the test.

- Record data: Record test data in detail for subsequent analysis and judgment.

- Environmental control: Control environmental parameters such as temperature and humidity during testing to minimize their impact on the test results.

IV. Conclusion

The quality of pressure sensors needs to be tested in multiple aspects, including appearance, pressure response, zero-point, circuit, and electrical performance. Comprehensive analysis and judgment of the test results are required. During testing, attention must be paid to safety, correct connections, the use of standard equipment, data recording, and environmental control to ensure the accuracy and reliability of the test.