This gauge is intended for accurately measuring vacuum degrees where negative (vacuum) pressure and high positive pressure are applied. Ideal for fire engines and other pressurized-water release equipment.

Features
・Halved scale --- Of the 270o central angle of the scale, a half indicates the vacuum over a range of 0.1 MPa to zero (0) and the remaining half is allotted to compressing pressure readings.
・No valve operation --- After measuring the vacuum, high pressure can be applied and measured without switching a valve.
・Four into one --- A single retard pressure gauge eliminates a vacuum gauge, a pressure gauge and 2 switching valves that were conventionally required for the same purpose.
・- No valve, no broken gauge --- No worry about breaking a vacuum gauge by valve operation error.