This rugged high vacuum gauge tube is ideal for heavy industrial applications such as vacuum furnaces and evaporators. There is no hot filament to accidentally burnout. If the tube is turned on at atmosphere it may require simple disassembly and cleaning. The replaceable anode attaches to a replaceable vacuum feedthru. The arc gap is adjustable. 
 
The Penning vacuum tube (named after its inventor, F. M. Penning) measures pressure as a function of the ion current flowing in a cold cathode pressure sensing tube which operates at high voltage and in a magnetic field. These tubes work with Myers Vacuum and CVC type: GPH-320, GPH-324 and GPT-450 vacuum gauges.