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

1. Application.

Pressure sensors are categorized based on their structural design, such as absolute pressure, atmospheric pressure, and differential pressure types. Absolute pressure sensors have a vacuum reference, making the measured value independent of atmospheric pressure. Atmospheric pressure sensors are referenced to the surrounding air, which means the sensing membrane is always exposed to the atmosphere. Factors like altitude, humidity, and seasonal changes affect atmospheric pressure, which in turn influences the readings. Additionally, fluid pressure can be measured from both sides of the diaphragm, allowing for differential pressure measurements. Different sensor designs are suitable for different applications.

2. Pressure Range.

The pressure range of a sensor is determined by its physical limits. The elastic diaphragm has a maximum pressure it can withstand before breaking. Typically, the maximum operating range is set at around 80% of the sensor's limit to prevent damage. Choosing an appropriate pressure range involves considering the sensor’s overpressure tolerance, the relationship between accuracy and range, and cost-effectiveness. It's important not to select a range that is unnecessarily large.

3. Accuracy.

Accuracy is crucial, especially when using pressure sensors for precise measurement rather than control. Semiconductor-based sensors are sensitive to temperature, so it’s essential to consider the operating temperature range. Proper calibration and thermal compensation techniques are often necessary to ensure reliable performance under varying conditions.

4. Electrical Requirements.

Sensors can be powered by either constant current or constant voltage sources. Constant current excitation helps reduce thermal drift, while constant voltage requires external components like thermistors for compensation. Some sensors use reference voltages to maintain stability regardless of power supply fluctuations. Battery-powered sensors may require recalibration after replacement due to differences in internal resistance and electromotive force. Low-power designs help extend battery life and reduce sensitivity drift.

5. Operating Methods.

Different environments demand different sensor configurations. Gas pressure measurements involve compressible fluids, while liquid pressure sensors must handle incompressible media. Long-distance signal transmission may require amplification, and digital output often needs conversion. Sensors used in harsh environments—like those with vibration, electromagnetic interference, or high shock levels—require robust construction, reliable seals, and proper shielding. In explosive environments, low excitation currents are used to avoid sparks.

6. Temperature Requirements.

Semiconductor pressure sensors are highly sensitive to temperature, experiencing both zero and sensitivity drifts. To mitigate this, advanced temperature compensation techniques are employed. The wider the operational temperature range, the more complex the compensation becomes. Therefore, selecting a sensor that matches the actual environmental conditions is essential for maintaining accuracy across all operating scenarios.

7. Sealing Requirements.

Sealing methods vary depending on the application, including rubber gaskets, O-rings, Teflon sheets, threaded connections, and welding. The choice of sealing material directly affects the sensor’s operational temperature range and durability. Proper sealing is critical to preventing contamination and ensuring long-term reliability, especially in corrosive or high-pressure environments.

With the rapid development of technology, the application of pressure sensors is expanding rapidly in China. Their sensing capabilities continue to evolve, finding use in various fields such as industrial automation, medical devices, and aerospace. As research into new materials, technologies, and methodologies progresses, the future of pressure sensor innovation looks promising, offering improved performance, reliability, and versatility.