While choosing a device or option to measure pressure in an engine, a component, a system can be complicated, the principles of differential pressure measurement are relatively simple.
As the name implies, this type of pressure measurement requires two different points. It is the measure of change between the two points, provided that one of the points is not a vacuum or the atmosphere.
If one of the points were to be a vacuum, it would be a measurement of absolute pressure by definition. The other option of measuring against the atmospheric pressure, actually the ambient pressure in relationship with the atmosphere, would be the gauge pressure.
Today’s Technology Advantages
The calculation and equation to determine differential pressure is complex and requires knowledge of the flow rate, cross-sectional flow, fluid density and fluid velocity. To make things a lot easier, software systems now complete these calculations, allowing for full automation of system control based on the readings obtained from the pressure measurement.
The average fluid velocity for differential pressure measurement is itself determined by fluid density, the acceleration due to gravity and the elevation or increase in the head of the fluid from the reference point.
With software systems and built-in calculations in devices designed for stand-alone types of differential pressure measurement models and devices are very user-friendly. They can be used for small systems to measure very slight pressure differences or with systems that may include materials that are chemical, corrosive or damaging to other types of sensors and devices.
There are many different systems that use this type of pressure measurement. The design of the device, the materials and even the ability to operate in extreme temperatures or environmental conditions will be important considerations. Getting the correct match in the differential measurement for pressure is important both for the lifecycle of the component as well as in the accuracy of the data that is collected.