ASTM B825-13

4.1 The present trend in environmental testing of materials with electrically conductive surfaces is to produce, under accelerated laboratory conditions, corrosion and film-forming reactions that are similar to those that cause failures in service environments. In many of these procedures the parts under test are exposed for days or weeks to controlled quantities of both water vapor and pollutant gases, which may be present in extremely dilute concentrations.

1.1 This test method covers procedures and equipment for determining the relative buildup of corrosion and tarnish films (including oxides) on metal surfaces by the constant-current coulometric technique, also known as the cathodic reduction method.

1.2 This test method is designed primarily to determine the relative quantities of tarnish films on control coupons that result from gaseous environmental tests, particularly when the latter are used for testing components or systems containing electrical contacts used in customer product environments.

1.3 This test method may also be used to evaluate test samples that have been exposed to indoor industrial locations or other specific application environments. (See 1.4 This test method has been demonstrated to be applicable particularly to copper and silver test samples (see (1)).² Other metals require further study to prove their applicability within the scope of this test method.

1.5 The values stated in SI units are the preferred units. The values provided in parentheses are for information only.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to become familiar with all hazards including those identified in the appropriate Material Safety Data Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use.