Terms are for industrial-based sensors and transducers. For Aerospace terms & definitions, please refer to Applications Notes & White Papers or refer to LVDT, RVDT and Force Sensor data sheets.

Flow – is the motion of a fluid. A fluid can be actual liquid, gases, or movable solids (i.e., granular or slurries).

Flow Rate – the time rate of motion of a fluid expressed as a fluid quantity per unit time.

Flow Velocity – the time rate of motion of a fluid; expressed as a distance of fluid travel per unit time.

Frequency, Natural – the frequency of free (not forced) oscillations of the sensing element of a fully assembled transducer.

Frequency Output – an output in the form of frequency that varies as a function of the applied pressure.

Full-Scale Output (FOS) – the output at full-scale pressure at a specified supply voltage. The signal is the sum of the offset signal plus the full-scale span.

Full-Scale Span – the change in output over the operating pressure range at a specified supply voltage. The SPAN of a device is the output voltage variation given between zero differential pressure and any given pressure. FULL-SCALE SPAN is the output variation between zero differential pressure and the maximum recommended operating pressure.

Gage Pressure – a form of differential pressure measurement in which atmospheric pressure is used as a reference.

Head Pressure – the height of a liquid column at the base of which a given pressure would be developed.

Hysteresis – the difference in output reading at a pressure point when the pressure point is approached first with an increasing pressure (from zero) and then with the decreasing pressure from full scale pressure.

Impact Pressure – the pressure in a moving fluid exerted parallel to the direction of the flow due to the flow velocity.

Input Impedance (resistance) – the impedance (resistance) measured between the positive and the negative (ground) input terminals at a specified frequency with the output terminals open.

Laser Trimming (automated) – a method for adjusting the value of thick film resistors using a computer-controlled laser system.

Leakage Rate – the maximum rate at which a fluid is permitted or determined to leak through a seal. The type of fluid, the differential pressure across the seal, the direction of leakage, and the location of the seal must be specified.

Line Pressure – the maximum allowable pressure safely applied to a transducer. Line pressure is also the maximum reference pressure allowable on a differential pressure transducer.

Linearity (end-point) – see Terminal Based Linearity (TBL).

Linearity (linearity error) – the deviation of the transducer output curve from a specified straight line. Linearity error is usually expressed as a % of span output.

Load Impedance – the impedance presented to the output terminals of a transducer by the associated external circuitry.

Long Term Drift – see Stability.