GOST 16931-71
GOST 16931−71 tinned copper Wire for electrotechnical purposes. The method of determining the quality of the tin coating (with Amendments No. 1, 2)
GOST 16931−71*
Group В79
INTERSTATE STANDARD
TINNED COPPER WIRE FOR ELECTRICAL PURPOSES
The method of determining the quality of the tin coating
Tinned copper wire for electrotechnical purposes. Method for determination of tinned covering quality
Date of introduction 1972−07−01
The decision of the State standards Committee of the USSR Council of Ministers dated 28 April 1971 811 N date of introduction is established 01.07.72
Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
* REISSUE (September 1999) with Amendments No. 1, 2 approved in March 1981, June 1986 (IUS 7−81, 9−86).
This standard specifies a method of determining the quality of the tin or tin-lead coating tinned copper wire intended for the manufacture of cables, wires and cords.
The standard fully complies ST SEV 2125−80 and publication of IEC 92−3.
(Changed edition, Rev. N 1, 2).
1. SAMPLING
1.1. The test shall be subjected to a wire that does not have mechanical damage, and stored under conditions specified in standards or specifications on the wire.
1.2. Samples of wire must be wound with the coils or the Bay without stretching and bending and mechanical damage to tin coating.
1.3. For testing should be selected three specimens from a coil or Bay.
Samples from stranded conductors shall be selected from the outer layer.
For round wire the length of the specimen, which test must be (the nominal wire diameter in mm).
Shaped wire length of the sample should be such that its test surface was not less than 942 mm.
Allowed to sample the specified length or surface to divide it into smaller pieces, taking them together for one sample.
1.2, 1.3 (Revised edition, Edit. N 1).
2. APPARATUS, MATERIALS AND REAGENTS
2.1. For the test to be applied:
volumetric flasks according to GOST 1770−74;
measuring cylinders according to GOST 1770−74;
calorimetric vessels according to GOST 1770−74;
thermometer according to GOST 28498−90;
gasoline according to GOST 3134−78;
broadcast on NTD;
trichloroethylene according to GOST 9976−94;
paraffin according to GOST 23683−89;
ammonium persulfate (NH)SO, h. e. a., according to GOST 20478−75;
ammonium hydroxide, NHOH, a density of 0.900 g/cm, h. e. a., according to GOST 3760−79;
dehydrated copper sulphate CuSO, h. e. a., according to GOST 4165−78;
distilled water, soft tissue, filter paper according to normative-technical documentation;
test solution: 10 g of ammonium persulfate dissolved in 500 cmof distilled water, adding 75 cmof ammonium hydroxide and diluted with distilled water to a volume of 1000 cm. The test solution should be prepared on the day of the test (check), avoiding heating of the solution above 35 °C;
control solution: 0,200 g of copper sulphate dissolved in distilled water, adding 75 cmof ammonium hydroxide and diluted with distilled water to a volume of 1000 cm.
Weighing batches of reagents for the preparation of solutions to be produced with accuracy up to 0,0001 g.
(Changed edition, Rev. N 1).
3. TESTING
3.1. The surface of the samples before the test, degreased by immersing them for 3 minutes in gasoline, ether or trichloroethylene, then dried with filter paper or soft cloth to the disappearance of the traces of fluid.
The ends of the samples or parts that make up one sample must be coated with paraffin, in this part, coated with paraffin, should not be considered when determining the length of the sample.
(Changed edition, Rev. N 1)
3.2. (Deleted, Rev. N 1).
3.3. The wire specimen was immersed for 15 min in a calorimeter vessel containing 100 cmof the test solution. The temperature of the solution must be (18±3) °C.
(Changed edition, Rev. N 1).
3.4. (Deleted, Rev. N 1).
3.5. After removing the sample from solution to produce a comparison of the color of the test solution with the color the same amount of control solution in the same calorimetric vessel.
3.6. The sample is considered satisfactory if the color of the test solution in the direction of the axis of the vessel will not be darker than the color of control solution.
3.5, 3.6. (Changed edition, Rev. N 1).