BS/EN 61605-2017 pdf download.Fixed inductors for use in electronic and telecommunication equipment – Marking codes.
This BS/EN 61605 specifies marking codes for fixed inductors.
The colour code specified in Clause 3 gives a colour coding for fixed inductors. It is intended for use with the values of the E3 to E24 series as specified in IEC 60063.
The code specified in Clause 4 gives a system for marking inductance values by means of digits and letters.
The code specified in Clause 5 gives a system for marking the tolerance on inductance values by means of letters.
The code specified in Clause 6 gives a system for marking of date codes on fixed inductors by means of letters and digits.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8601. Data elements and interchange formats — Information interchange — Representation of dates and times
3 Colour code for fixed inductors
3.1 General rules
Colour codes for fixed inductors should be expressed in “bands. If other shapes than bands are applied, the relevant specification shall prescribe their configuration, placement and identification.
Colour codes for fixed inductors shall consist of four bands. The first three bands shall indicate inductance values and the last band shall indicate tolerances.
Inductance values shall be expressed by two significant figures and another figure expressing multipliers.
Colour corresponding to significant figures, multipliers and tolerances shall be as given in Table 1.
The first two bands represent significant figures and the third band specifies the multiplier. The basic unit for the inductance value shall be expressed in pH. The first band shall be the one nearest to the end of the inductor and the bands shall be so placed and spaced that there can be no confusion in reading the coding.
Any additional coding on fixed inductors shall be applied in such a way as not to confuse the coding for value and tolerance.
These letter codes shall be placed after the inductance values.
5.2 Other tolerances
For tolerances for which a code letter has not been laid down, the letter A may be used. The letter A indicates that the tolerance is to be identified in other documents.
6 Date code system for fixed Inductors
6.1 Single-character code for year and month
Date codes of year and month in single-character shall be expressed in the code system shown in Table 5 and should be repeated every four years.
6.3 Four-character code for year and week
Where the date codes of the year and week of manufacture are required, the code system shall use four figures. The first two figures shall be the last two figures of the year and the last two figures shall be the numbering of the week. The numbering of the week shall be in accordance with Iso 8601, as follows:
Tenth week of 2019 = 1910
Forty-second week of 2024 = 2442.BS/EN 61605-2017 pdf download.