1 Scope
This standard specifies the terms and definitions, service conditions, technical requirements, test methods, inspection rules as well as marking, packaging and storage for damp heat test chambers (hereinafter referred to as “test chambers”).
This standard is applicable to the test chambers for damp heat test of electrotechnical, electronic and other products, parts and components and materials.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the standards indicated below. For undated references, the latest edition applies.
GB/T 191-2000 Packaging - Pictorial marking for handling of goods (eqv ISO 780:1997)
GB/T 2423.3-1993 Basic environmental testing procedures for electric and electronic products - Test Ca: Damp heat, steady state (eqv IEC 60068-2-3:1984)
GB/T 2423.4-1993 Basic environmental testing procedures for electric and electronic products - Test Db: Damp heat, cyclic (eqv IEC 60068-2-30:1980)
GB/T 2423.9-2001 Environmental testing for electric and electronic products - Part 2: Test methods - Test Cb: Damp heat, steady state, primarily for equipment (idt IEC 60068-2-56: 1988)
GB/T 14048.1-2000 Low-voltage switchgear and controlgear - General rules (eqv IEC 60947-1:1999)
JB/T 9512-1999 Climate environmental testing equipment and cabinet - Determination of sound power level of noise emitted
JJF 1059-1999 Evaluation and expression of uncertainty in measurement
3 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
3.1 test chamber
enclosed box and space where a certain part can meet the specified test conditions
3.2 temperature setpoint
desired temperature as set by the test chamber control device
3.3 achieved temperature
temperature at any point in the working space in the test chamber after stabilization
3.4 temperature stabilization
the state in which temperatures at all points in the working space reach the temperature setpoints and are maintained within a given tolerance range
3.5 temperature fluctuation
difference between the maximum and minimum temperatures at any point in the working space during any specified interval of time after stabilization
3.6 working space
part of the test chamber in which the specified conditions can be maintained within the specified tolerance range
3.7 temperature gradient
maximum difference in the mean temperatures between any two points in the working space at any time interval after stabilization
3.8 temperature rate of change
rate of the transition between two specified temperatures measured at the center of the working space, in ℃/min
3.9 temperature variation in space
difference between the mean temperature at the center of the working space and that at any other point in the working space at any time interval after stabilization
3.10 temperature extremes
maximum and minimum measured temperatures achieved in the working space after stabilization
3.11 saturation vapour pressure
vapor pressure at a constant temperature when the moisture in a given volume of air can no longer increase
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Service conditions
5 Technical requirements
6 Test methods
7 Inspection rules
8 Marking, packaging and storage
Annex A (Informative) Discrimination method for suspicious data
Annex B (Informative) Evaluation of uncertainty of temperature variation measurement
