ISO 764-2020 pdf free.Horology — Magnetic resistant watches.
1.This document specifies the minimum requirements and test methods for magnetic resistant watches.This document applies to magnetic resistant watches designed to withstand daily magnetic fields.Moreover, it indicates the marking which the manufacturer is authorized to apply to them.
2.Normative references The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO 3158,Timekeeping instruments — Symbolization of control positions
3.Terms and definitions For the purposes of this document, the following terms and definitions apply.
3.1 magnetic resistant watch:watch designed to withstand a homogeneous and continuous direct current magnetic field of 4 800 A/mencountered on a daily basis.3.2 enhanced magnetic resistant watch:watch designed to withstand a homogeneous and continuous strong direct current magnetic field equalor higher than 16 000 A/m encountered in close proximity
3.3 residual effect:difference of rates before and after the magnetic resistance test.
When observed during the magnetic fields application, watches shall not stop.
For electronic watches equipped with multiple motors，no motor shall stop during magneticresistance test.
4.other effects The examination of the watch shall not reveal any permanent deterioration affecting its functions or itsappearance (e.g. sticking hands, chronograph, calendar, etc.).
5.Test methods
5.1 Test conditions Magnetic resistant watches shall be tested on finished products and preparations for the test shall beas follows:
a) The test shall be carried out without bracelets, if removable.
b) The test room temperature shall be in a range of 23C ± 5 ℃.
c)During the measurement of all rates as specified in 5.3, the watch temperature shall not vary by more than ± 2°C.
The test apparatus used shall produce homogeneous and continuous direct current magnetic fieldsof the test value according to the directions specified in Admissible variations in magnetic fieldsstrength during the magnetic resistance test shall be 0 % to +5 %.ISO 764 pdf download.