This part of ISO 8502 describes a field test for the measurement of chloride ions using special detection tubes. With suitable surface sampling techniques, the test is applicable to steel surfaces before and after cleaning, as well as to painted surfaces between applications of coats. NOTE — ISO 8502-2, Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 2: Laboratory determination of chloride on cleaned surfaces, describes a laboratory method for the determination of chloride on a surface.