WHEN TO USE A CAPSULE GAUGE
When you need a precise low pressure measurement, a capsule gauge is the instrument to use.
Capsule gauges are used almost exclusively for measuring gaseous media.
These gauges are very precise with pressures that range lower than what the bourdon tube gauge can read.
They are often employed in low pressure pneumatic systems, breather valves, overpressure monitoring, filter monitoring and vacuum pumps, as well as many other situations where precision is a necessity.
HOW DO CAPSULE GAUGES WORK?
Capsule gauges get their name from an internal pocket created by joining two circular membranes along the outer edges. The membranes act as diaphragms. One has an opening in the center allowing the gas being measured into the capsule.
As pressure changes, the diaphragms expand or contract. The change in shape is relayed via deflection lever, which translates the change into a rotary movement. That rotary movement is displayed on the gauge’s face, providing a reading.
Gauges with similar designs have been used since the 1920s.
DURACHOICE'S TWO NEW LOW PRESSURE GAUGE DESIGNS
DuraChoice’s gauges are manufactured with dual scale dials in two measurement types - PSI/Bar or OZin2/inH2O (Ounces of force per square inch/Inches of water).
The scales that make up the latter pair are common measurements for low pressure applications. To give you some idea of the pressure levels being measured, there are 16 OZin2 per 1 PSI.
The PL254L is DuraChoice’s entry level capsule gauge, with a 2-1/2” dial under a removable acrylic window. It gauge has a brass connection and internals wrapped in a black steel case. A calibration screw, accessed by removing the window, allows the user to adjust the pointer as needed. As a point of reference, you can compare it to a WIKA Type 611.10.
The PLS254 is a heartier version of its brother. Cased in stainless steel, the PLS254L features a removable glass window instead of acrylic. It shares internals and connections with its black steel counterpart. You can compare that gauge to a WIKA 612.20, with the main difference being the DuraChoice gauge’s more compact 2-1/2” dial.
Both versions of the gauge come in the following ranges: 0/3 PSI, 0/5 PSI, 0/10 PSI, 0/15 PSI, 0/15 inH2O, 0/35 inH2O, 0/60 inH2O and 0/100 inH2O.