As a key component in industrial automation and various monitoring systems, the accuracy and reliability of pressure sensors are directly related to the operational efficiency and safety of the entire system. Therefore, accurate testing of pressure sensors to determine their performance and status is an important step to ensure stable system operation. In this article, we will introduce how to test pressure sensors in detail, including the test method, test procedure and matters to be noted in the test process.
Table of Contents
pressure sensor working principle
Before we delve into the testing methodology, it is important to understand how pressure sensors work. The principle of operation of pressure sensors is based on physical phenomena such as piezoelectric effect, strain effect and capacitance effect. When external pressure is applied to the sensor, the sensitive components inside the sensor will deform, resulting in changes in physical quantities such as resistance, capacitance or charge. By measuring the changes in these physical quantities, the magnitude of the external pressure can be deduced.
Test Methods
Test the pressure sensor is good or bad, you can start from the following aspects:
1. Appearance Inspection
- Check the casing: Ensure that the sensor’s casing is not worn or abraded to prevent damage to the sensor’s interior caused by the casing environment.
- Check the interface: Check that the sensor interface is in good condition to ensure fast connectivity and quality signal transmission.
- Check the fixing part: Ensure that the fixing part of the sensor is not loose or loosening, in order to prevent the unstable fixing from causing the measurement tray.
2. Pressure Test
- Power supply and connection: Supply power to the sensor and use a multimeter or other tool to connect the output of the sensor in order to output the change of detection voltage.
- Blow test: Blow gently through the air holes of the sensor with your mouth to observe the change of voltage on the multimeter.
- Standard Pressure Source Test: When conditions permit, use a standard pressure source to conduct a pressure test on the sensor. Sensor performance.
3. Zero detection
Non-voltage Detection: Place the sensor in a non-voltage state and use a multimeter to check its zero output. Arrangement or replacement.
4. Bridge Detection (Circuit Inspection)
- Using ohms: Measure the impedance between the input terminals and the impedance between the output terminals of the sensor using the ohms setting of a multimeter.
- Judge the status of the bridge: If the impedance is infinitely large, it means that the bridge is broken, and the sensor may be defective or the pins are not defined correctly.
5. Electrical Performance Inspection
- Zero Offset Detection: Record the output voltage of the sensor at zero pressure when it is under standard atmospheric pressure.
- Full scale test: Record the output voltage of the sensor at maximum pressure.
- Same test: Apply a small pressure change to the sensor and record the output voltage change.
- Linearity Test: Set a series of different pressure values within the measurement range of the sensor and record the corresponding output voltage values. To determine whether the linearity of the sensor is good or not.
Points to note in the testing process
Safety first: When conducting tests, ensure the safety of the test environment and test equipment, and prevent accidental injuries caused by improper operation.
Correct Connection: When connecting sensors and test equipment, ensure the correctness and speed of the connecting wires to prevent the test artifacts from being damaged due to poor connection.
Standard equipment: Where possible, standard pressure sources and other standard equipment should be used for testing to improve test accuracy and reliability.
Record data: During the test process, test data should be recorded in detail for subsequent analysis and judgment.
Environmental control: In the test process, the temperature and humidity of the test environment should be controlled as much as possible to minimize the impact of the environment on the test results.
Planning and retesting: ensuring accuracy
Scheduling and retesting are critical steps in ensuring the accuracy of pressure sensor measurements.
Standardized Testing
Testing with a known standard pressure source ensures that the sensor output signal is consistent with standard values.
Temperature Compensation
For temperature sensitive sensors, scheduling needs to take into account the effects of temperature variations.
Complex Long-Term Measurements
Sensors may lose accuracy over time, so regular retesting can help to identify problems in time and prevent system failure.
Conclusion
To summarize, testing the performance of a pressure sensor involves a number of aspects such as appearance, pressure response, zero point, circuitry, and electrical performance. By comprehensively analyzing and judging the test results, the performance and status of the sensor can be accurately assessed, and provide strong support for subsequent maintenance and use. Meanwhile, during the testing process, we need to pay attention to safety, proper connection, use of standard equipment, record data and control of the test environment to ensure the accuracy and reliability of the test.
