Diffusion silicon pressure sensor selection instructions - Database & Sql Blog Articles

TP-IP4220CZ6 5V 0.35PF breakdown voltage 6V SOT

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This sensor utilizes the piezoresistive effect, where strain resistors are formed on a single-crystal silicon wafer through doping and diffusion along specific crystal orientations to create a Wheatstone bridge. By leveraging the elastic mechanical properties of silicon and performing anisotropic micromachining, a diffused silicon sensor is fabricated that integrates both force-sensitive and force-to-electric conversion detection functions. This design ensures high sensitivity and stability in various applications.

Selection Instructions

1. Choose the appropriate sensors and transmitters based on the type of pressure being measured. Determine whether it's gauge pressure (relative to local atmospheric pressure), differential pressure, absolute pressure, or vacuum. When measuring liquid levels, ensure there is free atmospheric pressure above the surface or a sealed container. For sealed vessels, use a differential pressure product for accurate readings.

2. Define the product range. From a safety perspective, it's recommended that the working pressure falls within 60%-80% of the standard range. The overload pressure caused by system anomalies should not exceed the maximum allowed by the product. When measuring dynamic fluid pressure, consider the water hammer effect and increase the load accordingly.

3. Select the accuracy level. Different product grades offer varying parameters, with higher grades offering greater precision at a higher cost. Users can request specific accuracy metrics based on their application to achieve better performance at a lower cost. Accuracy is calculated using international least squares or end-base translation methods. Also, consider additional errors from zero drift and temperature coefficients during selection.

4. Choose the operating temperature range. Some transmitters include built-in temperature compensation, which is specified in the product description. For wide temperature ranges and high total accuracy, software-based temperature error correction can be applied during secondary meter data processing. Although the temperature coefficient may exceed standards beyond the compensation range, the product can still function. However, prolonged operation in extreme temperatures may reduce product lifespan.

5. Selecting differential pressure sensors and transmitters. General-purpose differential pressure devices are suitable for cases where the high-pressure side is greater than the low-pressure side. While diffused silicon sensors can handle negative differential pressures, the two ports are typically symmetrical, and the negative pressure port is usually not calibrated. If high symmetry is required, special notice must be given. The low-pressure side may be used in ultra-negative range applications.

6. Frequency response characteristics. Diffused silicon sensors have a higher natural frequency compared to other types. However, the frequency response is also influenced by the structural parameters of the pressure-guiding system and the rigidity of the sensor structure. These factors limit the overall response, so the pressure chamber plays a significant role in determining performance.

7. Compatibility with the measured medium. The sensor and transmitter interfaces, as well as the electronics housing, are made from different materials. Each material has varying compatibility with different media. To ensure optimal performance and avoid damage due to media mismatch, users should provide detailed information about the exact name, concentration, and temperature of the medium when placing an order.

Installation and Usage Precautions

Threaded products must be tightened using a wrench during installation and removal. Avoid over-tightening to prevent damage. Do not disassemble or install other parts of the clamp, as this may damage the joint components. Ensure no sharp objects protrude into the pressure-conducting hole to protect the sensitive diaphragm or isolation membrane. Never knock, hit, or drop the device.

The zero output of a diffused silicon sensor cannot be directly eliminated by the single-arm resistance method. Instead, use software zeroing, differential input trimming, or a T-type resistor network for calibration to ensure accurate readings.