Greisinger gdh 200 14 vacuum barometer and manometer greisinger gdh 200 14 p the greisinger gdh 200 14 is a vacuum barometer and manometer that measures the absolute pressure of air or non corrosive and non ionizing gases this small measuring device with a 4mm connection hose is ideal for non corrosive gases in large measuring areas p p applications measuring barometric air pressure overpressure measurements pneumatics tyre pressure and artificially created vacuum p p what s