Industrial Measurments Ltd - Torque Measurment

Talk Torque / Technical Terminology

ACCURACY:  The combined error of non-linearity, repeatability, and hysteresis expressed as a percentage of the full-scale output.

BRIDGE:  A strain gauge Wheatstone bridge configuration.

BRIDGE RESISTANCE:  The nominal value of the individual legs that make up a complete Wheatstone Bridge.

CALIBRATION:  The comparison of a transducer output against the output of a reference standard.

DEFLECTION:  The change in twist or length along the primary axis between no-load and rated load conditions.

FREQUENCY RESPONSE (BANDWIDTH): The range of frequencies over which the transducer output will follow the sinusoidally varying mechanical input within specified limits.

FULL SCALE/RATED CAPACITY:  The maximum value that a transducer is designed to measure.

HYSTERESIS: The maximum difference between output readings for the same measured point, one point obtained while increasing from zero and the other while decreasing from full scale. The points are taken on the same continuous cycle. The deviation is expressed as a percent of full scale.

INPUT IMPEDANCE:  The resistance measured across the excitation terminals of a transducer at room temperature, with no load applied, and with the output terminals open-circuited.

INSULATION RESISTANCE:  The DC resistance expressed in ohms measured between any electrical connector pin or lead wire and the transducer body or case.

LINEARITY:  The maximum deviation of the calibration curve from a straight line between zero and full scale, expressed as a percent of full scale output, and measured on increasing measured values only.

LOAD:  The torque or force applied to the transducer.

OUTPUT: The electrical signal measured at the output terminals, which is produced by an applied load to a transducer.

OUTPUT IMPEDANCE:  The resistance as measured on the output terminals of a transducer at standard temperature, with no load applied, and with the excitation terminals open-circuited.

OVERLOAD, SAFE:  The maximum load that may be applied to the transducer without causing a permanent change in its performance specifications.

PHASE SHIFT:  The phase angle between the output signal and the applied load.

RANGE:  The measured values, over which a transducer is intended to measure, specified by upper and lower limits.

REPEATABILITY:  The ability of a transducer to reproduce output readings when the same measured value is applied to it consecutively, under the same conditions, and in the same direction. Repeatability is expressed as the maximum difference between output readings as a percentage of full scale.

RESOLUTION:  The smallest change in mechanical input, which produces a detectable change in the output signal.

SENSING ELEMENT: The part of the transducer which reacts directly in response to the applied load.

SENSITIVITY:  The ratio of change in transducer output to a change in the value of the applied load.

SHUNT CAL (R-CAL):  The change in electrical output caused by placing a fixed resistor between the appropriate transducer terminals. Can be used "in the field" for quick calibration.

SPAN:  The algebraic difference between the limits of the range from zero to full scale.

STRAINGAUGE:  A measuring element for converting force, pressure, tension, etc., into an electrical signal.

TEMPERATURE, COMPENSATED:  The range of temperatures over which a transducer can operate up to full scale and still meet all specifications.

TEMPERATURE COMPENSATION:  The utilisation of supplementary devices, materials, or components within the bridge to minimise sources of error caused by changing temperature.

TEMPERATURE, OPERATING: The range of temperature over which a transducer may be safely operated up to full scale without causing failure, but specifications may not be met.

TEMPERATURE EFFECT ON SPAN: The change in rated output due to a change in ambient temperature.

TEMPERATURE EFFECT ON ZERO: The change in zero balance due to a change in ambient temperature.

TRANSDUCER:  A device (or medium) that converts energy from one form to another. The term is generally applied to devices that takes a physical phenomenon (pressure, temperature, humidity, flow, etc.) and converts it to an electrical signal.

ZERO ADJUSTMENTS:  Used when `setting up` a transducer to adjust the output signal to zero when no load is applied.

ZERO BALANCE:  The output signal of the transducer with rated excitation and with no load applied, usually expressed as a percentage of its rated output.