Pressure Transducer Terms

Defining Pressure Transducers

Transducers are defined using a number of different terms. Learn more about these terms and how they are used here. 

Zero Pressure – The minimum pressure that the transducer is expected to operate to. Can also be defined as 0% pressure.
The maximum pressure the transducer is expected to operate to. Can also be defined at 100% pressure.
The values within which the instrument is designed to measure, specified by its lower and upper limits (e.g. 0-500 PSI, 13-16 PSI, etc.). To provide a margin of safety, transducers are often selected so the system operating pressure is approximately 60% of the transducer’s maximum pressure rating. This may also be called the full scale pressure range.
Those values within which the pressure transducer is designed to measure. An example is 0-10 PSID (10 PSIUD or PSIU; or PSI Unidirectional) or ± 5 PSID (5 PSIBD or PSIB; PSI Bidirectional).
This is the difference between outputs at the pressure endpoints (i.e. The output at MEOP minus the output at zero pressure)
Also referred to as the “over-range capacity”, this is the maximum specified pressure which may be applied to the sensing element of a pressure transducer without causing a permanent change in the output characteristics (e.g. a zero shift beyond specified tolerance) or transducer performance. The proof pressure can be expressed as a specific pressure limit or as a multiple of the upper range value. Typically, this pressure is given as 1.5X MEOP.
The maximum fluid pressure that may be applied to the transducer’s pressure cavity without causing leakage of the fluid being measured from the pressure cavity. In some cases, burst pressure may pertain instead to a down line secondary containment or to the transducer body itself. While the transducer is designed to withstand this pressure without leakage, it will not function correctly after being exposed to this pressure. Typically, this pressure is given as 2.5X MEOP.
The ability for a transducer to contain the pressure fluid within the body of the transducer in the event that the initial diaphragm barrier bursts due to a high pressure event or manufacturing defect. This is typically accomplished by adding another secondary container to the body and an electrical header that can maintain the rated pressure of the transducer.
For submersible transducers, the maximum pressure (depth of water) supported by the transducer body, pressure port, and electrical receptacle (example: 15,000 PSI = 34,566 ft. of seawater).
For differential transducers only. This is the maximum allowable difference in pressure between the two pressure ports, without causing a permanent change in the output characteristics of the transducer (i.e. zero shift beyond specified tolerance).
For differential transducers only. This is the maximum static pressure that can be supported by both differential ports simultaneously. The maximum line pressure and the differential overload pressure are sometimes the same or very close.