Standard Test Methods for Evaluation of Total Sulfation Activity in the Atmosphere by the Lead Dioxide Technique

Importancia y uso:

5.1 Sulfur oxide gases are produced during the combustion of materials containing sulfur. These gases are precursors of atmospheric sulfuric acid, which has been shown to be injurious to living creatures and plants, as well as some inanimate materials such as metals, limestone and sandstone building materials.

5.2 Sulfur dioxide is moderately toxic and strongly phytotoxic to many species. Permissible ambient levels of SO₂ have been established by law.

5.3 When it is necessary to establish whether ambient air concentrations of sulfuric acid precursors, such as sulfur oxides, are present and to comply with legal criteria, manual and automatic monitoring systems specific for the individual sulfur species are used. Likely locations for monitoring sites for the estimation of concentrations and concentration trends over long periods of time can be screened conveniently using the PbO₂ candles or sulfation plates.

5.4 Atmospheric corrosion of metallic materials is a function of many weather and atmospheric variables. The effect of specific corrodants, such as SO₂, can accelerate the atmospheric corrosion of metals or structures significantly. The PbO₂ candle and sulfation plate test methods provide simple techniques to monitor SO₂ levels in the atmosphere independently to yield a weighted average result.

5.5 The results of these test methods are useful for characterizing atmospheric corrosion test sites regarding the effective average concentrations of SO₂ in the atmosphere at these locations.

5.6 These test methods are useful for determining microclimatic seasonal and long-term variations in effective average SO₂ concentrations.

5.7 The results of these test methods may be used in correlations of atmospheric corrosion rates with atmosphere data to determine the sensitivity of the corrosion rate to the SO₂ level.

5.8 These test methods may also be used with other test methods to characterize the atmosphere at sites at which buildings or other construction are planned in order to determine the extent of protective measures required for the materials of construction.

Subcomité:

D22.03.02

Referida por:

G0091-11R18, G0050-20

Volúmen:

11.07

Número ICS:

13.040.20 (Ambient atmospheres)

Palabras clave:

atmospheres; Huey plates; lead dioxide; lead dioxide candles; sampling; sulfation; sulfation plates; sulfur dioxide;