Reference Pressure

Reference Pressure is the pressure present on the reverse or negative side of a pressure sensing element.
For example the pressure reading will be zero when the total pressure measured on the positive side of the diaphragm equals the reference pressure.

Selecting reference pressure is one of the most important parameters to consider when specifying your requirements for a pressure sensing device.

It is often overlooked because the majority of pressure measurement applications have the same reference pressure and this has become the default selection if a pressure reference has not been specified. In a vast majority of applications the base pressure is atmospheric pressure, the air pressure created by the pull of earth’s gravity that surrounds everything.

Different types of reference pressures are:

●Absolute Reference Pressure
●Gauge Reference Pressure
●Differential Pressure Range

When it comes to selecting a pressure range it is important to think about the type of pressure reference required and clearly state it in your list of specification requirements.

Neglecting to specify the pressure reference could lead to the wrong device being supplied, which could lead to significant measurement errors especially at low pressure ranges.

For example if a gauge reference device is used to measure an absolute pressure there will be an offset equivalent to atmospheric pressure with all the readings and vice versa.