Differential pressure gauges are used to measure the difference in pressure between two sources. They find wide application in industry varying from filter resistance monitoring, to flow measurement. These are also used for level measurement in pressurised tanks. Differential pressure gauges work on the principal that the deflection of the sensing element depends on the difference of the pressure on either side of the element. The high pressure is applied to one side of the element and the low pressure on the other. The difference of pressure results in the deflection of the element, which is translated into a rotational motion and transferred to the pointer mechanism.

Standard Type :
These gauges find wide application due to their robust construction and a uniquely designed over pressure relief valve. This gauge uses a diaphragm sensing element with the HP and LP applied to either side. The deflection of the diaphragm is translated into a circular motion of the pointer via a pinned shaft and amplifier mechanism.

Standard Type With Static Pressure Indicator :
The static pressure under which a differential pressure gauge works is also an important parameter. This gauge incorporates a small pressure gauge on the main dial to indicate the static pressure at any point of time. This results in safer monitoring of pressure. This combination thus indicates both the differential pressure between the two sources, and the static pressure acting within the pressure chambers.

Economy Type :
This instrument is ideal for the safe and economical measurement of differential pressure. It finds application in filtration equipment, orifice and nozzle assemblies, level measurement and various other process applications. It incorporates a steel diaphragm sensing element. It is suited for use on gas and liquid lines where the fluids are compatible with the wetted parts.

This instrument incorporates a uniquely designed baffle which protects the sensing diaphragm against damage due to over pressure. As a result the instrument can safely with stand a positive overpressure of three times the scale value. The scale is distributed over an arc angle of 270° without diaphragm cushion or 180 with diaphragm cushion.

Low Pressure Capsule Type :
These gauges are used in the measurement of extremely low differential pressures. These gauges use a capsule pressure element with the pressures being applied on the inside and outside of the element. The deflection of the capsule is a function of the pressure difference and is used to indicate the same. The high pressure is applied in the capsule cavity while the low pressure is introduced into the case. These are suitable for air and clear, non-corrosive gas applications.

Twin Pointer Bourdon Type :
These gauges are used for simultaneously monitoring the high and low pressures on the same dial through two indicating pointers. The two pointers indicate the high and low pressures individually. The pointers show the two pressures in relation to each other, the difference being the gap between the two. These are suitable for gas and liquid applications. Also the temperature stability is higher. These gauges withstand full working pressure, applied separately or together.

These gauges are very useful for process applications as the operator can visualize the relation between the two pressures. If, in any case, one of the pressure sources is behaving in an erratic manner, the operator can immediately identify it, and take corrective measures. Ex. Inlet and outlet of turbines, pumps, filters, etc.