Pressure gauges are simple, cheap devices with local displays that show the pressure at a certain point in your process. This is one of the oldest forms of pressure measurement and it is still very common.
While classic mechanical pressure gauges are very reliable, wireless pressure gauges are becoming more and more common and will likely become popular with the advent of the Industrial Internet of Things.
Pressure gauge types
Mechanical pressure gauge
Most mechanical gauges don’t communicate with your process controller. They serve as indicators only and look something like this:
A traditional pressure gauge uses a mechanical system to measure pressure, with a Bourdon tube expanding and contracting based on the pressure applied. The entire system – rack, pivot, spring, pinion, and pointer – moves to show the pressure on the dial. It is literally just a dial that shows you the pressure – simple but effective.
You might have already encountered this dial on a tire pressure gauge, fuel pressure gauge, oil pressure gauge or in any other everyday situation where pressure is relevant.
Mechanical pressure gauges are very common and easy to read, but this is also their greatest limitation: you have to put your face next to it to read the pressure, which might be the simplest solution for your garden sprinkler’s water pressure gauge but can result in a lot of walking around and measurement accuracies in large factories.
Wireless or digital pressure gauge
Emerson has in its portfolio the Rosemount Wireless Pressure Gauge, also called a digital pressure gauge. It has the same design as a mechanical gauge, but it offers you the option of communication through wirelessHART. With the HART communication, you can monitor your process value and diagnose problems in your device or your process.
The wireless pressure gauge uses a strain-relief sensor that processes the signal digitally. Then it imitates the old interface with a tiny motor driving the pointer on the dial.
A wireless or digital pressure gauge gives you more stable and accurate pressure measurements, already converted to digital. And most importantly, the data can be collected remotely, without someone walking to every pressure gauge in a facility and noting down the numbers. The Rosemount even looks like a traditional pressure gauge.
Watch this video to find out more about how a digital pressure gauge works:
These articles will teach you more about this topic:
Absolute, gauge, and differential pressure: An explanation of all three subjects and what devices you need to measure them.
What is static pressure measurement?: A WishIKnew on the topic, breaking it down with a simple explanation and how-to.
What is differential pressure measurement?: A WishIknew on how differential pressure measurement works.
Product Review: Rosemount™ Wireless Pressure Gauge: Our review of the pressure gauge in this article – very interesting, so take a look at it.