How Do Vacuum Gauges & Controllers Work?

Vacuum gauges and controllers measure and regulate pressure in vacuum systems. They’re essential for processes where air or gas pressure must be precisely controlled—like in semiconductor manufacturing, packaging, or lab environments.

Vacuum gauges don’t measure vacuum itself—they measure pressure below atmospheric levels. Depending on the gauge type, they detect pressure using mechanical, thermal, or ionization principles. The choice depends on the vacuum range:

• Mechanical gauges (e.g., Bourdon tube, diaphragm) work best in low vacuum (above 1 mbar).
• Thermal conductivity gauges (e.g., Pirani, thermocouple) are used in medium vacuum (10⁻³ to 1 mbar).
• Ionization gauges (e.g., hot cathode, cold cathode) are used in high and ultra-high vacuum (below 10⁻³ mbar).

Each type converts pressure into an electrical signal that can be displayed or used for control.

No single gauge covers the full vacuum range. Systems often use multiple gauges to span from rough to ultra-high vacuum. Controllers must be compatible with the gauge types and pressure ranges in use.

For example, a Pirani gauge might handle rough vacuum, while an ion gauge takes over at lower pressures. The controller switches between them based on pressure thresholds.