Scales are adjusted with quick-acting positive mechanism. Heavy heat treated aluminum back plated have durable gray hammerloid finish. Not recommended for vacuum service beyond 5 in. 9-1, have mounting holes for easy installation. They may also be used as portable manometers and can be hung or attached to any vertical steel surface by magnetic mounting clips.
All parts are fully visible and readily accessible for cleaning.
All pressure connections are made from the back, with the micrometer zero scale adjustment in front at the base of the liquid column. Higher ranges and other special scales in Benelex panel. Red gage oil. Red gage oil is often preferred for readings in inches of water because of the longer scale and slower evaporation rate. This lessens the need for frequent re-zeroing and refilling.