Vacuum monitoring apparatus.

摘要

The invention provides a wide range pressure gauge comprising a thermal-conductivity gauge and a high-vacuum total or partial pressure gauge such as a hot-cathode ionization gauge or a residual gas mass spectrometer, mounted from a common flange. In order to allow the use of a filament (3) shorter than those conventionally used in thermal conductivity pressure gauges, means (49-54) are provided to maintain the filament temperature substantially constant over its entire pressure range. Pressure is measured by means (51, 52, 56-58) adapted to measure the power dissipated in the filament (3).