Pressure gauges
It is a measuring instrument for the pressure of fluids contained in closed containers. There are two types of pressure gauges, as indicated by the pressure of liquids or gases.
Vacuometer
An instrument is called a vacuum gauge that allows measuring the pressure when it is less than the pressure of the atmosphere. That is why it is said that vacuum gauges measure the vacuum.
Thermometer
Instrument used to measure temperature; the most common consists of a closed glass capillary tube and finished in a small tank that contains a certain amount of mercury or alcohol, which expands when the temperature increases or contracts when decreasing and whose volume variations are read on a scale graduated