Pressure sensor and transmitter common faults - Solutions - Huaqiang Electronic Network

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Pressure sensors and transmitters are commonly prone to several types of failures. The first issue is when the sensor fails to respond to pressure changes. In such cases, the first step is to check if the pressure port is leaking or blocked. If that's not the problem, verify the wiring connections and power supply. If the power is stable, try applying pressure and see if the output signal changes, or check if there is a zero output. If no change occurs, the sensor may be damaged, or there could be an issue with the instrument or other components in the system.

The second common failure is when the transmitter’s output does not change after pressurization, or it suddenly drops back to zero when pressure is released. This often indicates a problem with the sensor’s seal. A typical cause is using an incorrect sealing ring size, which can get compressed into the pressure port during installation, blocking the sensor. When pressure is applied, the medium might not enter the sensor, but once the pressure increases enough, the seal opens abruptly, causing sudden pressure on the sensor. To fix this, remove the sensor and test its zero output. If the zero is normal, replace the seal and retest.

The third type of failure is an unstable output signal. This can happen if the pressure source itself is unstable, or if the sensor or transmitter lacks sufficient interference resistance. Vibrations or internal sensor faults can also lead to erratic readings. It’s important to inspect the environment and ensure the sensor is properly mounted and shielded from external disturbances.

The fourth issue is when the transmitter’s reading significantly differs from the mechanical pressure gauge. Some deviation is normal, but it’s essential to confirm whether the difference falls within acceptable limits. If the deviation is too large, further calibration or inspection may be needed.

The last common problem involves the installation position of differential pressure transmitters affecting the zero output. Due to their narrow measurement range, even small misalignments can impact performance. During installation, the pressure-sensitive component should be positioned perpendicular to the direction of gravity. After installation, adjust the zero point to the standard value to ensure accurate readings.