ASTM B845-97 - 10.5.1997
 
1. Scope

1.1 The techniques described in this guide pertain to mixed flowing gas (MFG) tests containing corrosive species that are applied to evaluate devices containing electrical contacts such as slip rings, separable connectors, electromechanical relays or switch contacts. These techniques may be relevant to other devices, but it is the responsibility of the user to determine suitability prior to testing.

1.2 The MFG tests described in this guide are designed to accelerate corrosive degradation processes. These accelerations are designed such that the degradation occurs in a much shorter time period than that expected for such processes in the intended application environment of the device being tested. Application environments can vary continuously from benign to aggressively corrosive. Connectors and contacts within closed electronic cabinets may be affected by an environment of different severity than the environment on the outside of such cabinets. In general, indoor environments are different than outdoor environments. The MFG tests described herein, being discrete embodiments of specific corrosive conditions, cannot be representative of all possible application environments. It is the responsibility of the test specifier to assure the pertinence of a given test condition to the specifier's application condition.

1.3 The MFG tests described herein are not designed to duplicate the actual intended application environment of the device under test. An extended bibliography, Section 10, that provides information which is useful to test specifiers to assist them in selecting appropriate test methods is included in this guide. The bibliography covers the scope from application condition characterization, single and multiple gas effects, and material and product effects to key application and test variables as well as discussions of atmospheric corrosion processes.

1.4 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 establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

 
2. Referenced Documents

IEC 68-2–60 (second edition)

Environmental Testing--Part 2: Tests--test Ke: Flowing mixed gas corrosion test, 1995

IEC Standard 68-2–43

Basic Environmental Testing Procedures, Test Kd Hydrogen Sulfide Test for Contacts and Connections

IEC Technical Trend Document 68-2–60

TTD Environmental Testing, Corrosion Tests in Artificial Atmosphere at Very Low Concentration of Polluting Gas(es)

IEEE P1156.1

Environmental Specifications for Computer Modules (Draft 4 June 10, 1992--unapproved) Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.

B542-24

Standard Terminology Relating to Electrical Contacts and Their Use

IEC Standard 68-2–42

Basic Environmental Testing Procedures, Test Kc Sulphur Dioxide Test for Contacts and Connections Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.

B810-01a(2022)

Standard Test Method for Calibration of Atmospheric Corrosion Test Chambers by Change in Mass of Copper Coupons (Includes all amendments and changes 4/11/2023).

B825-19(2024)

Standard Test Method for Coulometric Reduction of Surface Films on Metallic Test Samples

B826-26

Standard Test Method for Monitoring Atmospheric Corrosion Tests by Electrical Resistance Probes

B827-05(2020)

Standard Practice for Conducting Mixed Flowing Gas (MFG) Environmental Tests

EIA-364B-TP65

Mixed Industrial Gas Test Procedure Available from IHS, 15 Inverness Way East, Englewood, CO 80112, http://www.global.ihs.com.

B808-10(2026)e1

Standard Test Method for Monitoring of Atmospheric Corrosion Chambers by Quartz Crystal Microbalances (Includes all amendments and changes 5/20/2026).