What is a gauge pressure sensor?

In some applications the exact pressure or vacuum being generated is not of key importance. Instead, you just want to understand how much the pressure or vacuum differs in comparison to atmospheric pressure.

For example, the level of a liquid in an open tank will change with variation in atmospheric pressure. A gauge pressure sensor allows this to be measured and compensates for those atmospheric pressure changes.

Medical applications also make regular use of gauge pressure sensors, for fluid extraction from wounds, in hyperbaric chambers, and ex-vivo blood pressure measurements. In such situations, the pressure, or vacuum, to be developed is often small, and requires fine control in order to avoid harm to the patient, or damage the biological sample of interest.

A gauge pressure sensor measures the pressure at its port with respect to the local atmospheric pressure. 

Our pressure sensors work as Gauge pressure sensors, measuring positive and negative pressure relatively to atmospheric pressure.

Tip: This Gauge pressure sensor can be calibrated. See details about the pressure sensor calibration here. Gauge sensors pressure measurements are dependent of atmospheric pressure.

Cross-section of a typical gauge pressure sensor.

A gauge pressure sensor measures pressure relative to the local atmospheric pressure

What applications are gauge pressure sensors used in?

If the pressure measurements you intend to perform needs to be relative to the local atmospheric pressure, then you will need to use a gauge pressure sensor.  

What are the other possible types of pressure sensing?

  1. Absolute pressure sensor : with this type of sensor, the absolute measurement is made possible by measuring the target pressure relative to the known pressure of an absolute vacuum. This can be compared with measuring temperature in Kelvin, where the lowest possible temperature is 0 °K. Absolute pressure sensors are useful whenever elevation above sea level (altimeter measurement) is required, but they can also be used in food industry where partial vacuum is needed to seal food packs for example.

  2. Relative pressure sensor: Sometimes you don't need to know the absolute pressure in a system. Instead, what would matter is the difference between two points in the system. In such situations, you can use differential pressure sensors. The measurements made are fully independent of atmospheric pressure, unlike gauge sensors. It is possible to use two gauge pressure sensors installed one after the other to get the pressure between two different points of a microfluidics setup.