How does digital pressure gauge work?
- Issue Time
Digital pressure gauges use pressure transducers to provide a reliable, high accuracy reading on an attached digital display. Our display takes the signal from the transducer and processes it according to your settings to give you a pressure reading in the unit of measure of your choosing - adjusting it for activated features like tare or peak hold.
Unlike analog, or dial, pressure gauges, digital gauges are built for reliability in demanding conditions. Dial gauges require constant re-calibration and repair. One major dial gauge manufacturer estimates that in a typical plant, 25% of dial gauges need immediate replacement, and another 40% need corrective action. It’s a mess caused by inadequacies inherent in analog gauges.
On the other hand, digital pressure gauges are inherently durable. Especially our gauges. They’re built to withstand the tough stuff, like vibration, over pressure, water hammer, etc.
There is one moving part in a digital pressure gauge - the diaphragm. It’s a thin metal (316L SS) layer with an electric circuit attached to it’s back. As the diaphragm flexes under the pressure, the resistance on the circuit changes in direct proportion to the applied pressure. This is known as piezoresistive technology, and the circuit is called a Wheatstone bridge.
The diaphragm is definitely thin, and needs to be handled with care. But its designed to take the even pressure that comes when installed. In fact, it can handle an over pressure 2X it’s full scale and still operate normally.
In contrast, a dial gauge is all mechanical, full of moving parts and small gears. They are especially prone to over pressure and vibration. It doesn’t take much to send them to the re-calibration lab, or to break them altogether.
Vibration is a common problem in process plants, and pumps are a major source of that vibration. Monitoring pumps is critical (more on that later), but whatever gauges will be installed on or near pumps need to be able to handle the vibration. Our digital pressure gauges work perfectly in vibrating environments. Unlike a dial gauge, they’re legible under vibration as well.
In extreme environments, the display can be tethered to the transducer with a cable to prevent additional wear and tear on the electronics, further increasing the gauge’s lifespan. Tethering the gauge also increases it’s operating temperature, and is generally a good way to remove the electronics from process stresses.