scope:

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.