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 its 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 it's designed to take the even pressure that comes when installed. In fact, it can handle an over pressure 2X its 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 overpressure 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 digital gauge 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 digital pressure gauge also increases its operating temperature, and is generally a good way to remove the electronics from process stresses.
Our digital pressure gauges come with the most complete set of gauge functions on the market. Our most basic model offers all but a few of them. These are easily accessible (and easily locked) through the digital gauge display interface.
Tare
The Tare function is very popular. It allows you to cancel out the existing pressure. It measures change from the moment you enable the function.
This is sometimes used to calculate weight. Our digital pressure gauges can be programmed to calculate weight in a hydraulic system. Once programmed, you can enable the Tare function to cancel out existing weight before a load is applied.
Peak Hold
Holding the peak pressure is another popular function. Peak Hold does exactly that. If you’re trying to monitor pressure peaks, then this is the function for you.
The electronic pressure gauge will still be actively reading pressure, you’ve just told it to not display anything but the peaks. This setting can be activated and reset at any point.
Units Of Measure
Choosing your unit of measure is part of the ordering process. But we’ve still included the option to change it at any time. Pre-programmed units include psi, bar, kPa, kgcm2, mbar, MPa, inHg, ftH2O, cmHg, inH2O, mmHg.
You can also create a custom unit of measure. This is done by entering a multiplier, or a conversion factor. For example, converting psi to ftH2O is easy, simply multiplying by 2.31. So if it wasn’t already a standard option in the pressure gauge’s menu system, you could use the custom multiplier option to make the conversion.
Bar Graph
Our digital pressure gauges come with a bar graph. This let’s your instrumentation tech and your operators see pressure as a percentage of scale, rather than just a hard measurement. You simply set the low and high point for your bar graph, and the gauge does the rest!
Auto Off
To conserve battery life, each electronic pressure gauge comes with an auto-off setting. This simply turns the gauge off after it’s been on for a certain number of seconds. All you have to do is tell the gauge how many seconds to stay on.
Max/Min
Finally, you can toggle between the current reading, the most recent highest (maximum, or peak) reading, and the most recent lowest (minimum) reading. This is done right on the main screen by pressing the S, Select, or Down button, depending on the model you have.
Digital pressure sensors are an important part of any process that uses pressurized vessels or lines. They serve as vital safety tools to control pressure, and they help you keep your equipment running smoothly. When used correctly, electronic pressure gauges are one of the most valuable instruments you can have.
Some Some common applications of digital pressure sensors are:
Pump Control
Filter & Control Valve Monitoring
Hydraulic Weight/Force
Difficult/Harsh Points of Measurement
Pump Control
We tend to think of pump control as turning pumps on and off. And when we’re discussing liquid level, that’s exactly the function they provide, a means of controlling when pumps run and, in the case of a VFD, at what RPMs.
The best way to control a pump is not with level sensors, though they play a role too. It’s with pressure gauges. It also happens to be the old way, practiced for years as an effective method for keeping pumps, seals, and bearings working for many years at a time with no downtime. But as older engineers retired and newer technologies became the focus of later generations, we stopped using digital pressure gauges to control pumps.
Electronic pressure gauges are used to monitor the suction and discharge pressure on pumps. The differential between the two is critical, as are the individual readings. Operating the pump at the right differential pressure will ensure a long life of uninterrupted service. Learn more about pump control with pressure gauges.
Filter & Control Valve Monitoring
Filters and valves need to be monitored constantly to know how they’re operating. Like a pump, filters and valves need two gauges installed, one on the upstream and downstream side.
A pair of digital pressure gauges will let you see flow decrease over time as the filter gets dirty and eventually clogs. This decrease in flow will be represented by an increase in differential pressure.
Control valves need gauges installed to show the operator how open or closed it is. This will also give an indication of flow via differential pressure. The pressure drop across the control valve is a critical value. Too big of a drop could create an overpressure on the upstream side, and starve the process on the downstream side.
Hydraulic Weight/Force
Pressure inside of a hydraulic column can be converted to pounds of force (or weight) by factoring in the area of the hydraulic ram. Our digital pressure gauges allow you to put in customer multipliers to measure in whatever unit of measure you need. So to measure weight from a hydraulic column, simply calculate your multiplier. The formula for this is area = pie X the radius2(A=πR^2). Enter the calculated multiplier and label the unit as LBS.
This is done to monitor force in hydraulic systems. A unique application of this concept weighs hay bales on a forklift to avoid spending thousands on an industrial weight scale. Virtually anything could be weighed in this manner as long as you have an accurate measurement on the hydraulic column inside the forklift.
Difficult/Harsh Points Of Measurement
Our tethered digital pressure gauges are ideal for placing the display and electronics in a safer or more convenient location. In many industrial settings, the pressure port is in a difficult place. Often the conditions are harsh right at the point of measurement - either the temperature is high, or vibration can be severe, or it may be particularly oil, dirty, or wet.
The best way to make pressure measurement easy in these environments is to tether the digital gauge display to the transducer with a cable. This removes the electronics of the display from harsh conditions, and allows you to place the display in a much more convenient location.
Tethered digital pressure gauges come in handy in applications ranging from pump monitoring to pressure testing.
FAQ's
