This Recommendation applies to direct recording electrical measuring instruments@ which are used for recording the instantaneous@ effective or mean values of one or more measured quantities as a function of time. It refers to strip@ crum and disc recording instruments@ namely: - ammeters; - voltmeters; - single-phase watt meters@ var meters and phase meters; - frequency meters; - ohmmeters. It applies to those instruments which incorporate rectifiers or diodes and to thermocouple instruments@ also to certain accessories used with such apparatus@ namely: - shunts; - series resistors@ inductors and capacitors. In the case of other accessories associated with instruments inasmuch as the calibration has been made of the instrument together with the accessory@ the Recommendation is applicable to the combination of instrument and accessory. The Recommendation also applies to electrically measuring equipments provided that the recording electrically measuring instrument (receiver) only is considered@ and the relationship between the non-electrical quantity and the electrical one is known. (Furthermore@ it applies to recording instruments incorporating electronic devices in their auxiliary circuits.) The recommendation is not applicable; - to recording instruments having a square wave response greater than 90% on a square wave with an amplitude equal to the effective range and a frequency of 5 Hz; - to recording instruments incorporating@ in their measuring circuits@ amplifying or electronic devices (other than rectifiers or diodes); - to integrating recording instruments; - to indirect recording instruments.