Pressure sensor application to different areas of selection principles - Database & Sql Blog Articles

1. Application

Pressure sensors can be categorized based on their structure into absolute pressure, atmospheric relative pressure, and differential pressure types. Absolute pressure sensors have a vacuum reference, making the measured pressure independent of atmospheric conditions. Atmospheric pressure-based sensors are connected to the atmosphere, so their readings are influenced by environmental factors like altitude, humidity, and seasonal changes. Differential pressure sensors measure the difference between two fluid pressures, which is essential in many industrial applications. Choosing the right type depends on the specific use case and the environment in which the sensor will operate.

2. Pressure Range

The pressure range of a sensor is determined by its design and the mechanical limits of its diaphragm. Exceeding this range can cause damage or failure. Typically, sensors are rated for 80% of their maximum pressure limit to ensure reliability. Selecting an appropriate range involves considering the sensor’s overpressure tolerance, the relationship between accuracy and range, and cost-effectiveness. Over-specifying the range may lead to unnecessary costs without significant benefits.

3. Accuracy

Accuracy is crucial when using pressure sensors for measurement tasks. Semiconductor-based sensors are sensitive to temperature variations, so it's important to select a sensor that operates within the intended temperature range. Calibration and temperature compensation techniques are often required to maintain precision in varying conditions.

4. Electrical Requirements

Sensors typically require either constant current or constant voltage excitation. Constant current sources help reduce thermal drift by balancing the temperature coefficients of the bridge resistors. In contrast, constant voltage sources may require external components like thermistors for compensation. The choice between the two depends on the application and desired performance. Additionally, some sensors use proportional or fixed excitation methods, with the latter offering better stability against power supply fluctuations.

5. Operating Conditions

Different environments affect sensor performance. For instance, gas pressure measurements involve compressible fluids, while liquid pressure measurements require consideration of incompressibility. Long-distance signal transmission may require amplification to prevent signal loss. Digital outputs may need conversion from analog signals, and sensors must handle shocks, vibrations, and electromagnetic interference. Proper installation, shielding, and material selection are critical for reliable operation.

6. Temperature Considerations

Semiconductor-based pressure sensors are highly sensitive to temperature changes, leading to both zero and sensitivity drifts. Effective temperature compensation is essential, especially in wide temperature ranges. While broader ranges offer more versatility, they also increase calibration complexity and reduce overall accuracy. Therefore, selecting the right sensor requires understanding the operational temperature range and accuracy needs.

7. Sealing Requirements

Proper sealing is vital for maintaining sensor integrity. Common sealing materials include rubber gaskets, Teflon, and welded joints. The choice of seal affects the sensor’s operating temperature and pressure capabilities. Ensuring tight seals helps prevent contamination and maintains long-term reliability, especially in harsh environments.

With the rapid development of technology, the application of pressure sensors is expanding across industries. Their role in automation, control systems, and data acquisition continues to grow. As research advances in new materials, sensor designs, and integration techniques, future developments will focus on improving accuracy, durability, and adaptability in diverse environments.