Any type of vacuum pressure transducer is designed to be used in a vacuum or with below atmospheric pressure. While there may be some variation, it is perhaps more important to see it as a sub-atmospheric pressure option.
A vacuum pressure transducer will actually measure the presence of specific molecules found in a gas, and the number of molecules present with their creation of changes in the pressure. This is done using several different technologies or design systems including mechanical, variable capacity, and strain gauges, which are the most common.
A vacuum pressure transducer responds to changes in pressure by changing shape. This change creates fluctuations to the electric resistance which is transmitted as a reading. There are different types of strain gauges, which are considered to be very rugged and dependable, often selected when used in a hostile environment.
The mechanical deflection design has a diaphragm, bellows, or a tube design that measures changes in pressure through the component. A connection to the pressure sensor is able to record even the slightest variations of change of the shape on an ongoing basis.
Variable capacitance vacuum pressure transducer, are considered to be very accurate since the vacuum between the two plates, can be controlled and kept constant. This ensures a very clean and accurate reading even in environments where vibration and extreme wear are present.
Considering the specifics of use, as well as the accuracy of reading, will be important when selecting a vacuum pressure transducer. Overall, these are the most accurate types of transducers for most applications, with most designed to provide 0.1% FS accuracy, even when exposed to significant temperature change during the testing.