Glossary of Terms
A measurement term meaning one billionth.
A standard from the National Electrical Manufacturers Association, which defines explosion-proof enclosures for use in locations classified as Class I, Groups A, B, C, or D, as specified in the National Electrical Code.
A standard from the National Electrical Manufacturers Association, which defines enclosures with protection against dirt, dust, splashes by non-corrosive liquids and salt spray.
Case An older US case standard for panel meters, which requires a panel cutout of 3.93 x 1.69"
Normal-Mode Rejection (NMR)
The ability of a panel meter to filter out noise superimposed on the signal and applied across the SIG HI to SIG LO input terminals. Normally expressed in dB at 50/60 Hz.
In an ideal system, the input-out relationship is linear (i.e., straight line). Any departure from straight line is expressed as non-linearity. Two methods are used for measurement. The “best straight line” approach compromises the end points and situates the line to give the most optimistic answer. Rustrak non-linearity measurement is based on end point calibration which gives a truer value and a standard, more convenient method for calibrator and recalibration.
Identifies undesired signals that are not common to both input terminals of differential amplifier. Also known as Series Mode.
National Pipe Thread, tapered, the fitting that is brazed or welded onto the RTD or thermocouple sheath, standard sizes are from 1/8 inch to 1 inch.