Applies to transducers with electrical inputs and outputs for making measurements of a.c. electrical quantities with a nominal frequency between 5 Hz and 1 500 Hz. The output signal may be in the form of an analogue direct current or in digital form. Supersedes IEC 60688-1 (1980) and IEC 60688-2 (1988). This consolidated version consists of the second edition (1992), its amendment 1 (1997) and its amendment 2 (2001). Therefore, no need to order amendments in addition to this publication.