ISO 8502-4:1993

Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 4: Guidance on the estimation of the probability of condensation prior to paint application

May be used to establish whether conditions at the job site are suitable for painting or not. The method specified is based on measuring air temperature and relative humidity, calculating the dew-point, measuring the steel surface temperature, and estimating the minimum surface temperature (above the dew-point) that is needed to avoid condensation under the prevailing environmental conditions. Annex A contains a table for determination of dew-point.