scope:

Introduction

The locally prevailing air temperature, the moisture content in the air (% relative humidity), and the temperature at which moisture will condense on surfaces (dew point) are commonly called the ambient conditions. If these conditions are not within the ranges required by a coating specification during surface preparation or coating application, problems in obtaining a protective film with a long-term performance are likely to occur.

Because of concerns for these problems, specifications require the monitoring of ambient conditions using specialized instruments and test methods before the start of work and periodically during the work. Measurement of these conditions is especially important when weather conditions change during the course of a work shift.