Pressure Measurement Devices for HVAC-R
Pressure Measurement Overview
Pressure is defined as a force per unit area. It is however much easier to use pressure to describe the influences of liquids, gases and steam in a pipe or duct rather than force. Pressure measurement devices work by measuring the difference between a reference pressure and the pressure to be measured.
The reference pressure used dictates the type of measurement being taken and is typically broken into three categories namely absolute, gauge, and differential.
Types of Pressure Measurement
Absolute pressure is zero-referenced against a perfect vacuum.
Gauge pressure is zero-references to atmospheric pressure. Gauge pressure is equal to absolute pressure minus the current atmospheric pressure. For example, at sea level under reference conditions gauge pressure values would equal absolute pressure minus 14.696 psi.
Differential pressure is simply the difference between two measurement pressures in reference to each other.
Pressure measurement devices vary from simple columns of liquid to complex, electronic transmitters with extreme accuracy. Siemens SITRANS P is a proven range of electronic pressure measurement products for all pressure applications. From simple fixed range transducers to the ultra high performance P500, SITRANS P covers it all.
06/14/2012 | Author: Ryan.Shea@siemens.com