Bringing advanced technology to sensors

Glossary

Absolute Pressure: Pressure measured using vacuum as reference. Usually expressed in psia.

Differential Pressure: The pressure difference between two pressure sources, which usually are neither vacuum nor the ambient pressure. Usually expressed in psid.

Gage Pressure: Pressure measured using ambient pressure as reference. Usually expressed in psig.

Sealed Gage Pressure: Pressure measured using a fixed pressure as reference. The fixed pressure is usually 1 atm (14.697 psia). Usually expressed in psis.

Atmospheric Pressure: Pressure of the air surrounding the earth. This pressure varies depending on altitude and weather conditions.

Barometric Pressure: see atmospheric pressure

Ambient Pressure: Pressure surrounding the device.

Ambient Temperature: Average temperature surrounding the device.

Analog Output: A voltage or current signal that is a continuous function of the measured parameter.

ANSI: American National Standards Institute

NEMA: National Electrical Manufacturers Association

Pressure Range: The specified range over which a transducer is intended to measure, specified by the upper and lower limits.

Compensated temperature range: Temperature range in which a sensor meets all claimed specifications.

Operating temperature range: Temperature range in which a sensor can operate without damage. But specifications claimed may not be met in this range.

Storage temperature range: Temperature range in which sensor can be safely stored. At these temperatures, sensor is not supposed to be power-supplied or to operate.

Compensation: Material added to a device to reduce a known error.

Span: The arithmetic difference in transducer output signal measured at the specified minimum and maximum operating pressures.

Sensitivity: The ratio of output signal voltage change to the corresponding input pressure change. Sensitivity is determined by computing the ratio of span to the specified input pressure range.

Reference Temperature: The temperature used as reference in measuring transducer errors.

Full-Scale: The algebraic difference between endpoints. Where one endpoint is actual offset voltage and the other endpoint is the upper limit of the range.

Reference Pressure: The pressure used as a reference in measuring transducer errors.

Offset Voltage: The transducer output signal obtained when the reference pressure is applied.

Over-Pressure-Maximum: The maximum normal mode (measured) pressure that can be applied without changing the transducer's performance or accuracy beyond the specified limits. This would be applied to either pod of a differential transducer. This is also called PROOF PRESSURE.

Common-Mode Pressure-Maximum: The maximum pressure that can be applied to both ports simultaneously of a differential transducer.

Burst Pressure: The maximum pressure that can be applied to a transducer without rupture of  transducer case.

Best Straight Line (BSL): The best straight line chosen such that the true transducer response curve contains three points of equal maximum deviation.

Temperature Coefficient (TC): The error band resulting from maximum deviation of a transducer output parameter (such as offset or span) as temperature is varied from 25ºC to any other temperature within the specified range. It is usually measured in ppm/ºC or µV/V/ºC.

Repeatability: The error band expressing the ability of the transducer to reproduce an output signal parameter (such as offset or span), at specified pressures and temperature, after exposure to any otter pressure and temperature within the specified range.

Stability: The error band expressing the ability of a transducer to maintain the value of an output parameter (such as offset or span) with constant temperature and pressure inputs.

Interchangeability: The error band defined by the maximum signal deviation obtained when a transducer is replaced by any other transducer of the same type with equivalent pressure inputs and temperature ranges.

Most Probable Error: The error band obtained by computing the square root of the sum of the squares of all applicable errors specified for the transducer.

Worst-Case Error: The error band obtained by simple addition of all applicable errors specified for the transducer.