Designed for pressure measurements as low as a few inches of water. The 1929 is available in spans from 30″ H2O to 10 psi and utilizes a unique sensing element. The 1929 is composed of a stack of diaphragm capsules, each consisting of two plates contoured into a convex/concave configuration to nest into one another resulting. This results in a low internal volume element developing large forces to drive the mechanism in extremely low pressure ranges. The SOLFRUNT gauge case was designed with an integral wall between the measuring element and window, and a pressure relieving back for increased safety. To use the gauge with corrosive or viscous fluids, the measuring element may be filled and attached to a Mansfield & Green Type L or Type ST diaphragm seal.