Differential Gauges

A differential gauge is a device designed to measure the difference in pressure between two pressure sources. This can be on gas, air or liquid applications. When installed, one port is connected on the low side and the other on the high side. This will show a pressure drop indicated on the display.

S.M. Gauge supply a range of Differential Gauges, widely used across many industries. Below is a selection of many different types we can offer. In addition to our range of standard ‘off the shelf’ instruments we can also supply to your required specification including non-standard connections and even customised dials featuring your company logo.

Please see our enquiry form or call our sales team on +44 (0)117 9654615 to discuss your requirement.

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Differential Gauges FAQs

What is a differential gauge?

Differential pressure gauges are widely used in industrial processes to measure the condition, level and flow of liquids and gases. Whereas a standard pressure gauge measures pressure at a single point, differential pressure gauges measure the difference between two different levels of pressure. The main benefit of differential gauges compared to other measuring methods is their simplicity.

How do differential gauges work?

Differential gauges work by connecting a single device to two separate pressure points, the difference in pressure between the two points is shown on a single dial or digital display. The ability to simultaneously measure the difference between two different pressure levels reduces the errors associated with having to take two separate pressure readings and work out the difference between them.

Where are differential gauges used?

Filtration systems

Where filters are used to prevent liquid or gas from being contaminated with foreign particles a differential gauge is used to determine when the filter needs to be changed. As the filter traps unwanted particles they reduce the flow of gas or liquid between one side of the filter and the other. This creates a difference in pressure between the two sides. When the difference meets a set point, it means that the filter is ready to be changed. The advantage of using a gauge to determine the optimal point at which to change the filter is efficiency. The filter only gets changed when necessary, thereby maximising the life of the filter and the overall efficiency of the system.

Flow rate within pipes

The flow of liquid or gas within a pipe is determined by the pressure on the liquid and the diameter of the pipe. When it is necessary to control the flow rate within a pipe a device known as a venturi can be used to restrict the diameter of the inside of the pipe. Reducing the diameter of the pipe increases the pressure on the substance being measured. To measure the difference in pressure a differential pressure gauge takes readings from either side of the venturi and displays the difference between the two.

Liquid level monitoring

A differential pressure gauge can be used to monitor the level of liquid in a tank by installing a pressure detector at the bottom of the tank and one at the top where no liquid is present. As the level of the liquid in the tank changes the pressure on each of the detectors changes. The difference between the two pressures is equal to the height of the liquid multiplied by the gravity exerted by the liquid.