Applies to X-t recorders used for the measurement of voltage and current which measure and record analogue electrical quantities as a function of time. Also applies to non-interchangeable accessories and accessories of limited interchangeability (e.g. shunts, impedance-elements) if they are used with the recorder and the adjustments have been made for the combination. IEC 1143-1 and IEC 1143-2 cancel and replace IEC 484 (1974).