Standard Practice for Estimating the Time of Wetness Potential at an Outdoor Weathering Site using a Cotton Wick Sensor

Importancia y uso:

5.1 Time of wetness is one of most important parameters in weathering. The presence or absence of water may affect the rate and type of degradation. The presence or lack of water does not matter for some materials.

5.2 Testing locations can be categorized by their time of wetness. The total time of wetness can be related to the amount and type of weathering that is achieved.

5.3 There are several ways to measure rainfall amount and duration, but not for condensation. In some climate zones, condensation can be considered as the most important factor contributing to surface wetness.

5.4 The purpose of this practice is to permit the estimation of the time of wetness at a particular location for the intent of characterizing that site. The actual time of wetness of any particular surface, or a specific specimen on exposure requires the use of a different technique such as that described in Practice G84.

5.5 This technique cannot be used to directly measure the time of wetness of any specific specimen.

5.6 The wick shall be mounted to a non-conducting substrate such as glass. Based on historical data, glass is the preferred substrate. Other non-conducting materials such as rubber, plastic, and wood, may be used but will not yield the same results as glass. The substrate shall be indicated in the test report.

5.7 This technique was first developed and verified c1931 by Charles F. Kettering4.

Subcomité:

G03.02

Volúmen:

14.04

Palabras clave:

exposure location; time of wetness;