Template For ENG STDS
WORLDWIDE
ENGINEERING Test Procedure GMW14729
STANDARDS
Procedures for High Humidity Test
1 Introduction
Note: Nothing in this standard supercedes applicable laws and regulations.
Note: In the event of conflict between the English and domestic language, the English language shall take
precedence.
1.1 Purpose. This procedure describes two options of high humidity testing (water fog and wet-bottom) which
are typically used to evaluate the influence of high humidity environments to coated substrates. This influence
is usually measured by testing physical and mechanical properties before and after exposure.
1.2 Applicability. Not applicable.
1.3 Remarks. Not applicable.
2 References
Note: Only the latest approved standards are applicable unless otherwise specified.
2.1 External Standards/Specifications.
ASTM B117 ASTM D1193 ISO 6270-2
2.2 GM Standards/Specifications.
None
2.3 Additional References.
Product or Material Specifications.
Subsystem Technical Specifications.
Component Technical Specification.
Part Drawings.
3 Resources
3.1 Facilities. Not applicable.
3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid
calibration label.
--```````,```````,,```,-`-``,```,,,`---
3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables
as specified in this standard shall be determined correctly with respect to their physical definition.
3.2 Equipment.
3.2.1 Option A: Water Fog. The apparatus for fogging humidity exposure shall consist of:
3.2.1.1 A fog/environmental chamber.
3.2.1.2 Suitable water supply conforming to ASTM D1193 Type IV.
3.2.1.3 A supply of suitably conditioned compressed air.
3.2.1.4 One or more atomizing nozzles.
3.2.1.5 Provisions for heating the chamber and the necessary means of control (refer to ASTM B117,
Appendix X.1 for further details regarding the construction of the apparatus).
3.2.2 Option B: Wet Bottom. The apparatus shall consist of the chamber design as defined in ISO 6270-2
Section 5.1, Climatic Chamber.
© Copyright 2015 General Motors Company All Rights Reserved
June 2015 Page 1 of 3
Copyright General Motors Company Order Number: 02088910
Provided by IHS under license with General Motors Company Sold to:KTL [700166100749] - CHOEY@KTL.RE.KR,
No reproduction or networking permitted without license from IHS Not for Resale,2016-01-18 02:55:25 UTC
Template For ENG STDS
GM WORLDWIDE ENGINEERING STANDARDS GMW14729
Note: During “wet-bottom” generated humidity cycles, insure that visible water droplets are found on the samples
to verify proper wetness.
3.3 Test Vehicle/Test Piece. Test specimen preparation shall be per the applicable product or material
specification, or per agreement between the requester and the test analyst.
3.4 Test Time. Not applicable.
3.5 Test Required Information. Not applicable.
3.6 Personnel/Skills. Not applicable.
4 Procedure
4.1 Preparation. Humidity test environment and duration of test shall be per the applicable product or material
specification, or per agreement between the requester and tester.
4.2 Conditions.
4.2.1 Environmental Conditions. The apparatus for humidity exposure shall be installed in a room with an
ambient atmosphere where room temperature is 23 °C ± 5 °C and < 75% relative humidity (RH).
4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such
requirements shall be specified on component drawings, test certificates, reports, etc.
4.3 Instructions.
4.3.1 Option A: Water Fog. Test temperature and humidity within the exposure zone shall be:
Temperature: 38 °C ± 2 °C
Humidity: ~100% RH
4.3.2 Option B: Wet-Bottom. Test temperature and humidity within the exposure zone shall be:
Temperature: 40 °C ± 3 °C
Humidity: ~100% RH
5 Data
5.1 Calculations. Not applicable.
5.2 Interpretation of Results. Evaluations (pre-test and post-test), rating methods, and acceptance criteria shall
be specified within engineering documentation which includes: Material Specifications, Subsystem Technical
Specifications, Component Technical Specification, and Part Drawings.
5.3 Test Documentation. Test documentation must include Type of used equipment (Option A or B).
5.3.1 Option A: Fogging. Basic test information to include sample identification, hours of duration, results of
evaluation and any other pertinent information should be included in the report. Additionally, the following
parameters shall be monitored and recorded on a daily basis (weekends and holidays are exceptions):
5.3.1.1 The temperature within the exposure zone 38 °C ± 2 °C.
5.3.1.2 The fog collection rate, based on 80 cm2 of horizontal test area (1.0 mL to 3.0 mL per hour). At least two
collectors per atomizing tower shall be placed in the exposure zone and shall be distributed to provide a
--```````,```````,,```,-`-``,```,,,`---
representative measure of the fog collection rates throughout the chamber.
5.3.1.3 The humidifying tower temperature and pressure. These parameters shall be adjusted as needed to
produce the specified operating conditions.
5.3.2 Option B: Non-Fogging. Basic test information to include sample identification, hours of duration, results
of evaluation and any other pertinent information should be included in the report.
6 Safety
This standard may involve hazardous materials, operations, and equipment. This standard does not propose to
address all the safety problems 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.
© Copyright 2015 General Motors Company All Rights Reserved
June 2015 Page 2 of 3
Copyright General Motors Company Order Number: 02088910
Provided by IHS under license with General Motors Company Sold to:KTL [700166100749] - CHOEY@KTL.RE.KR,
No reproduction or networking permitted without license from IHS Not for Resale,2016-01-18 02:55:25 UTC
Template For ENG STDS
GM WORLDWIDE ENGINEERING STANDARDS GMW14729
7 Notes
7.1 Glossary. Not applicable.
7.2 Acronyms, Abbreviations, and Symbols.
GSSLT Global Subsystem Leadership Team
RH Relative Humidity
8 Coding System
This standard shall be referenced in other documents, drawings, etc., as follows:
Test to GMW14729
9 Release and Revisions
This standard was originated in October 2005. It was first approved by Global Materials Testing Team in
December 2006. It was first published in February 2007.
Issue Publication Date Description (Organization)
1 FEB 2007 Initial publication.
2 NOV 2010 Removed revision date from ASTM D1735 and ISO 6270-2 references
in 2.1, 3.2.2, 4.3.1, 4.3.2, 5.3.1, and 5.3.2. (Corrosion GSSLT)
3 JUN 2015 Updated to 2015 GMW template. (Materials - Corrosion GSSLT)
--```````,```````,,```,-`-``,```,,,`---
© Copyright 2015 General Motors Company All Rights Reserved
June 2015 Page 3 of 3
Copyright General Motors Company Order Number: 02088910
Provided by IHS under license with General Motors Company Sold to:KTL [700166100749] - CHOEY@KTL.RE.KR,
No reproduction or networking permitted without license from IHS Not for Resale,2016-01-18 02:55:25 UTC
