Today is...
Monday, September 24, 2018
Welcome to, the global online
community of automation professionals.
Featured Video...
Featured Video
Wiring and programming your servos and I/O just got a lot easier...
Our Advertisers
Help keep our servers running...
Patronize our advertisers!
Visit our Post Archive
Difference in Absolute and Relative Pressure Gauge
Questions about the difference between absolute pressure gauge and relative pressure gauge

good day everyone,

what is the reading in my absolute pressure gauge and my relative pressure gauge if i measure lets say a 2 bar pressure? its just that i want to know their difference in reading when measuring same pressure.

could you help me please.
thank you

2 out of 2 members thought this post was helpful...

If you are measuring 2 bar(A) pressure using an absolute pressure gauge and a relative pressure gauge, readings will be:

Absolute Pressure gauge: 2 bar
Relative Pressure gauge: 1 bar (Considering 1 bar atmospheric pressure)

At any point, readings on the Absolute pressure sensor = (Relative pressure sensor reading+ Atmospheric pressure)

2 out of 2 members thought this post was helpful...

All pressure measurement is differential, that is, the measurement is made relative to, or with respect to, a reference pressure.

A gauge or gage pressure measurement references local atmospheric pressure. A tire pressure gauge makes a gauge pressure measurement references atmospheric pressure.

An absolute pressure measurement references absolute zero, a hard vacuum, or as close to absolute zero as can be managed. A barometer makes an absolute pressure measurement referencing a vacuum inside the barometer.

A differential pressure measurement references second pressure source, so a differential measuring transducer/transmitter has two ports, where the high low side pressure references by low side pressure; 'subtracting' the low side from the high side pressure to report a differential pressure.

1 out of 1 members thought this post was helpful...

Absolute measures from absolute zero pressure (i.e. total vacuuum; "outer space"), i.e the measurement includes atmospheric pressure.

Relative measures the difference between two pressures. One is typically the reference, which is sometimes atmospheric pressure (i.e. open to "air").