Industrial measurement glossary
Short definitions of terms used throughout the site.
Accuracy
Qualitative closeness of agreement between a measured quantity value and the true quantity value; product literature may use the word more loosely for a numerical specification.
Calibration
Operation that establishes the relationship between indication and reference quantity values under specified conditions.
DAQ
Data acquisition; hardware/software that samples, converts and records measurement signals.
Differential pressure
Difference between two pressures applied to the measurement system.
HART
Bidirectional industrial communication protocol used with intelligent field instruments and host systems.
LRV
Lower range value; the process value assigned to the low end of a configured transmitter range.
Measurand
The quantity intended to be measured.
Metrological traceability
Property of a measurement result whereby it can be related to a reference through a documented unbroken chain of calibrations, each contributing uncertainty.
Repeatability
Measurement precision under a defined set of repeatability conditions.
Resolution
Smallest change in a measured quantity that causes a perceptible change in indication.
RTD
Resistance temperature detector; temperature sensor based on predictable resistance change.
Span
Difference between upper and lower range values.
Transmitter
Instrument that converts a sensed measurement into a standardized or digital output.
Uncertainty
A non-negative parameter characterizing the dispersion of quantity values attributed to a measurand based on the information used.
URV
Upper range value; the process value assigned to the high end of a configured transmitter range.