BS EN ISO 15720:2001

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Apparatus
5 Reagent
6 Safety hazards
7 Procedure
8 Examination
9 Precision
10 Test report
Annex A (informative) Useful guidelines for examining
        samples
Annex B (informative) Significance and use
Bibliography

Gives equipment and techniques for determining porosity in noble metal coatings, particularly electrodeposits of gold, palladium and palladium-nickel alloy and clad metals used on electrical contacts.

This test method covers equipment and techniques for determining porosity in noble metal coatings, particularly electrodeposits of gold, palladium and palladium-nickel alloy (70%to 90%palladium) and clad metals used on electrical contacts.

The gel-bulk procedure is not as sensitive to small pores and is more complex than porosity tests involving gaseous corrodants (see ISO14647 and ISO15721). It also involves more chemicals, preparation and auxiliary equipment.

This test is intended to be used for quantitative descriptions of porosity (such as number of pores per unit area or per contact) only on measurement areas where coatings have a sufficiently low pore density such that the corrosion sites are well separated and can be readily resolved. As a general guideline this can be achieved for pore densities up to about 25/cm².

Other porosity testing methods are outlined in ISO10308. Detailed critical reviews of porosity testing are also available. Other porosity test methods are described in ISO12687, ISO14647 and ISO15721.