BS EN 60063:2015

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 Number series
5 Application of an E series
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications
Bibliography

Gives series of preferred values for the resistance of resistors and for the capacitance of capacitors.

This International Standard provides series of preferred values for the resistance of resistors and for the capacitance of capacitors. The definition of such series with a defined numeric resolution is a basic prerequisite for the marking and coding of capacitors and resistors with their respective capacitance or resistance values as described in IEC60062 . NOTE The number series defined in this standard are based on progressive ratios of [Formula removed.], with r = 3 · 2 i , and i being a whole number in the range of 0 to 6, hence e.g. of [Formula removed.] . This system of progressive ratios had been established prior to the 1952 release of the first edition of this standard 1 as a consequence of the standardisation of tolerances at±5%,±10%and±20%and the related commercial practice. An adoption of the ISO practice, based on a [Formula removed.] system, was never considered achievable.