The vibration monitoring industry has specialized jargon that is commonly used when talking about vibration sensors, accelerometers and associated applications. It's important that you understand common terminology to communicate effectively with vibration monitoring, reliability, condition monitoring and process automation professionals. We hope you find our glossary useful to find specialized terms and definitions used across vibration, condition monitoring and predictive maintenance.



The pressure above (or below) atmospheric. Represents positive difference between measured pressure and existing atmospheric pressure. Can be converted to absolute by adding actual atmospheric pressure value.


Transfer characteristic expressing the ratio of output voltage to the input signal of an amplifier. For a voltage amplifier: expressed as volts/volt, as mV/mV, or as dimensionless number. For a charge amplifier: expressed as millivolts per Pico Coulomb (mV/pC).


The minimum and maximum values of gain that are available in an amplifier without causing any degradation in performance parameters beyond the limits of the specification. For a charge amplifier: expressed as from ____mV/pC to ____mV/pC.

GROUND LOOP (Earth Loop)

The closed electrical circuit formed by the connection of a ground wire to several ground terminals at different locations.


Refers to the presence or absence of an electrical connection between the "low" side (signal return) of the transducer element and the portion of the transducer intended to be in contact with the test structure.