This Dixon Valve GL105 vacuum gauge has a 1/4" National Pipe Taper (NPT) male threaded lower mount, a 2" display face and an ABS (acrylonitrile butadiene styrene) case with a polycarbonate crystal, and measures vacuum to 30" of mercury (Hg). The gauge displays 0.5" Hg increments on a white dial face with a black aluminum pointer and has ASME B40.1, Grade B accuracy (plus or minus 3-2-3 percent of span). Vacuum is measured using a bronze bourdon tube and the gauge has a brass movement with a polyester segment for extended wear. This vacuum gauge has an operating temperature range of -40 to +150 degrees F and is suitable for use in a variety of applications, such as in petrochemical and chemical manufacturing.

Pressure gauges are instruments used to measure the pressure of a gas or liquid inside a vessel and, often, to help ensure the optimal amount of pressure for a given application. Pressure gauges can range from everyday instruments, such as those used to measure the air pressure in a car or bicycle tire, to highly accurate gauges used in mechanical and industrial processing. Most often, pressure gauges measure pressure relative to another reference, such as to ambient air. An example of a pressure gauge measuring relative to ambient air is a tire pressure gauge or a blood pressure gauge. A pressure gauge can also measure differential pressure, which is the difference in pressure between two points, such as when measuring liquid flow along various points in a pipeline. An absolute pressure gauge measures pressure relative to a perfect vacuum, such as an atmospheric or barometric pressure gauge. All types of pressure gauges include either a male or a female mount to connect to the vessel where pressure is being measured and display results on a dial with varying increments of measure across a given range.

Dixon Valve & Coupling Company manufactures pipe and hose fittings and accessories. The company, founded in 1916, is headquartered in Chestertown, MD.