ASTM D7539 Standard Practice for Humidity Regulation of Pavement Marking Coatings test Boards using a laboratory defines a standard environment with a temperature of 23±2°C, a relative humidity of 50± 5%, and no airflow for the normal regulation and testing of paints, vernizes, lacas, and related materials.
Significado e uso

5.1 The drying rate of organic coatings varies with temperature, air flow and relative humidity. Em particular, the drying rate of water-based coatings depends on the evaporation of water and is therefore more dependent on relative humidity than solvent-based coatings or 100% solid coatings. Without some control over drying conditions, the drying rate of water-based coatings measured in the laboratory under ambient conditions cannot be adequately replicated. A test chamber providing a device for controlling relative humidity above ambient humidity and minimizing the effect of changes in airflow at ambient room temperature is described. If needed,

5.2 This practice is particularly useful for testing the drying rate of waterborne pavement marking (traffic) revestimentos, where rapid drying at high ambient humidity is an important feature. For waterborne traffic coatings, test chambers can be used to assess dryness to non-absorption at high ambient humidity (test method D711) and washable resistance (practice D7377 and D7538).

Prática padrão ASTM D7539-2015 para regulação de umidade de placas de teste de revestimentos de marcação de pavimentos usando laboratórios

Etapa 1: Escopo

1.1 Specification D3924 defines a standard environment with a temperature of 23±2°C, a relative humidity of 50± 5% and no airflow for the normal conditioning and testing of paints, vernizes, lacquers and related materials. The practice describes a test chamber that allows the control of relative humidity above the ambient relative humidity and minimizes air flow to regulate the test board at elevated relative humidity and room temperature.

1.2 Valores em polegadas a libras serão considerados valores padrão. Os valores dados entre parênteses são transformações matemáticas de unidades SI e são apenas para referência e não são considerados padrão.

1.3 Esta norma não se destina a abordar todas as questões de segurança, caso existam, associado ao seu uso. É responsabilidade dos usuários desta norma estabelecer práticas adequadas de segurança e saúde e determinar a aplicabilidade das restrições regulatórias antes do uso..