Noun
vacuum gauge (plural vacuum gauges)
(physics) An instrument that is used to measure very low pressures of gases.
A vacuum gauge is used to measure the pressure in a vacuum—which is further divided into two subcategories: high and low vacuum (and sometimes ultra-high vacuum ). Source: Internet
Thermocouple as vacuum gauge seeAlso A thermocouple can be used as a vacuum gauge over the range of approximately 0.001 to 1 torr absolute pressure. Source: Internet
The thermocouple was first used as a vacuum gauge by Voege in 1906. Source: Internet
To distinguish a negative pressure, the value may be appended with the word "vacuum" or the gauge may be labeled a "vacuum gauge." Source: Internet