Why are two pressure sensors in the same space giving different readings?

April 22, 2019

Room pressure readings are useful and often necessary in a range of spaces. However, two pressure transducers in the same space might not always present the same reading. A variety of circumstances can have an impact on the reading of a pressure sensor.

1. Different Locations

Being in different locations in a room can alter the readings of a transducer. If, for example, one transducer is near a duct and another is closer to a door, the readings are likely to differ. Circumstances such as air flowing out of a duct or into a room through an open door can altepressure gauger room pressure; as such, differently placed sensors would have different readings.

2. Overpressure

One or both of the sensors could have been subjected to overpressure conditions. Some transducers are rated for overpressure, but not all of them. If too much pressure over the rated limit of a sensor is applied, future readings and accuracy can be impacted.

3. Accuracy and Drift

Different accuracies between the two sensors can be another cause of discrepancy. Without the same accuracy, the readings from the two transducers are less likely to match. Another cause of discrepancy could be that one of the sensors drifted. If the sensors do not have a high stability year over year, the readings are more likely to shift.

4. Mounting Orientation

Mounting orientation impacts the readings of a sensor. Whether mounted vertically or horizontally, the effect of gravity will cause a shift in readings on a transducer.

5. Reversed Tubes

For differential pressure transducers, another thing can impact readings. If the tubes have accidentally been reversed for one or both of the transducers, each sensor would present a different reading.


Topics: HVAC/R, pressure transducers