Thermal gauges, out of all the available gauge technologies, offer excellent value for measuring rough vacuum pressure, but even UHV and XHV system can benefit from them. All thermal gauges operate by heating a filament and exposing it to the vacuum system. This video explains why, how, and which thermal gauges can be successfully used on ultra-high vacuum systems, and how they operate to achieve both accuracy and durability.

Ionization gauges convert residual molecules to positively charged ions, and then attract them to a negatively charged collector where they create a measurable current. Modifications to high vacuum ionization gauges can optimize their performance at a very low pressure.

No one gauge technology will provide pressure measurement throughout the range of vacuum. Combining vacuum sensors can produce a gauge capable of measuring pressure better than with any single technology. After having highlighted the properties of individual sensors, i.e. Pirani, Capacitance Manometer, Hot Filament Ionization, and IMG, this video shows some sensor combinations to measure pressure in a vacuum system.