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.

Range – see Operating Pressure Range.

Ratiometric – ratiometricity refers to the ability of the transducer to maintain a constant sensitivity, at a constant pressure, over a range of supply voltage values.

Ratiometric (ratiometricity error) – at a given supply voltage, transducer output is a proporation of that supply voltage. Ratiometricity error is the change in this proportion resulting from any change to the supply voltage. Usually expressed as a % of full-scale output (FSO).

Reference Pressure – an independent pressure, ranging from zero pressure to some maximum pressure capability of a transducer used as a relative standard to compare the measured pressure.

Repeatability – the difference in output reading at a given pressure point when the pressure is applied consecutively from the same direction.

Resolution – the magnitude of output step changes as the pressure is continuously varied over the range. This term primarily applies to potentiometric sensors. Resolution for other pressure transducers is generally limited by sensitivity of the readout device. Usually expressed in % of full-scale output (FSO).

Response Time – the length of time required for the output of a transducer to rise to a specified % of its final output value as a result of a step change of input pressure.

Room Conditions – ambient environmental conditions under which a transducer must commonly operate; established as follows:

(a) Temperature: 25 ±110°C (77±18°F).
(b) Relative Humidity: 90% or less.
(c) Barometric Pressure: 26” to 32” Hg.
Note: Tolerances closer than shown may frequently be specified for transducer calibration and test environments.

Sealed Pressure Transducer – (PSIS) measures pressure with respect to an internal reference chamber sealed at atmospheric pressure. Gage pressure measurements below 100 PSI may require corrections for changes in atmospheric pressure and thermally induced ‘reference” pressure errors.

Self Heating – internal heating of a transducer as a result of power dissipation.

Sensing Element – that part of a transducer that responds directly to changes in input pressure.

Sensitivity – the change in output per unit change in pressure for a specified supply voltage or current.

Sensitivity Shift – a change in sensitivity resulting from an environmental change such as temperature.

Sensor – a popular term sometimes used to describe a transducer. Technically a sensor is an un-compensated, low-level output device that converts the measured to an electronic detectable change, (i.e., resistance, capacitance, and inductance).

Signal Conditioning – to process the form or mode of a signal so as to make intelligible to, or compatible with, a given device, including such manipulation as pulse shaping, pulse clipping, compensating, digitizing, and linearizing.

Span – the algebraic difference between the upper and lower limits of the pressure range.

Stability – the ability of a transducer to retain its performance characteristics for a relatively long period of time, unless otherwise stated; stability is the ability of a transducer to reproduce output readings obtained during its original calibration at room conditions for a specified period of time. It is typically expressed as within % of full-scale output (FSO) for a period of “X” months.

Static Calibration – a calibration recording output vs. pressure at fixed points at room temperature.

Static Error Band – the error band applicable at room temperature.

Static Pressure – the pressure of a fluid exerted normal to the surface along which a fluid flows. A fluid can be liquid or gaseous.

Storage Temperature Range – the range of temperature between minimum and maximum that can be applied without causing the sensor to fail to meet the specified operating characteristics.

Strain Gauge – a sensing device providing a change in electrical resistance proportional to the level of applied stress.

Supply Voltage (current) – the voltage (current) applied to the positive and negative (ground) input terminals.