quantity not essential for the performance of an item but affecting its performance NOTE - For electric devices, typical influence quantities may be temperature, humidity, pressure.quantity which is not the subject of the measurement and whose change affects the relationship between the indication and the result of the measurement NOTE 1 - This term is used in the 'uncertainty' approach. NOTE 2 - Influence quantities can originate from the measured system, the measuring equipment or the environment. NOTE 3 - As the calibratio...quantity that is not the measurand but that affects the result of the measurement NOTE - For example, temperature of a micrometer used to measure length.in the field of power electronics any quantity generally external to a power supply which may affect its performance
A quantity which is not the subject of the measurement but which influences the value of the output signal for a constant value of the measurand.