IEC 60068-2-2:2007

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Application of tests for non heat-dissipating specimens
  versus tests for heat-dissipating specimens
  4.1 General
  4.2 Ascertaining high or low air velocity in the test
       chamber
  4.3 Application of tests with sudden change of temperature
       versus tests with gradual change of temperature
  4.4 Testing of heat-dissipating specimens
  4.5 Temperature monitoring
  4.6 Packaging
  4.7 Diagrammatic representations
5 Test descriptions
  5.1 General
  5.2 Test Bb: Dry heat for non heat-dissipating specimens
       with gradual change of temperature
       5.2.1 Object
       5.2.2 General description
  5.3 Test Bd: Dry heat for heat-dissipating specimens with
       gradual change of temperature that are not powered
       during the conditioning period
       5.3.1 Object
       5.3.2 General description
       5.3.3 Energising the specimen
  5.4 Test Be: Dry heat for heat-dissipating specimens with
       gradual change of temperature that are required to be
       powered throughout the test
       5.4.1 Object
       5.4.2 General description
6 Test procedure
  6.1 Confirmation of performance
  6.2 Working space
  6.3 Thermal radiation
  6.4 Mounting
  6.5 Severities
       6.5.1 General
       6.5.2 Temperature
       6.5.3 Duration
  6.6 Preconditioning
  6.7 Initial measurements
  6.8 Conditioning
       6.8.1 Steady state conditions
       6.8.2 Absolute humidity
  6.9 Intermediate measurements
  6.10 Final temperature ramp
  6.11 Recovery
  6.12 Specimen with artificial cooling
  6.13 Final measurements
7 Information to be given in the relevant specification
8 Information to be given in the test report

IEC 60068-2-2:2007 Deals with dry heat tests applicable both to heat-dissipating and non heat-dissipating specimens. For non heat-dissipating specimens, Tests Bb and Bd do not deviate essentially from earlier issues. The object of the dry heat test is limited to the determination of the ability of components, equipment or other articles to be used, transported or stored at high temperature. These dry heat tests do not enable the ability of specimens to withstand or operate during the temperature variations to be assessed. In this case, it would be necessary to use IEC 60068-2-14 Test N: Change of temperature. The dry heat tests are subdivided as follows:
- Dry heat test for non heat-dissipating specimens with gradual change of temperature, Bb.
- Dry heat tests for heat-dissipating specimens with gradual change of temperature, Bd;
with gradual change of temperature, specimen powered throughout, Be. The procedures given in this standard are normally intended for specimens that achieve temperature stability during the performance of the test procedure. The main changes from the previous edition are as follows: Tests Ba and Bc have been deleted since they were more severe tests than Test Nb, IEC 60068-2-14: Change of temperature. Secondly it was considered justified to delete the 3 % value on the temperature difference between the chamber air and the wall temperatures. Thirdly it is proposed that the test specimen be powered throughout the test where required; and, finally, the annexes have been removed.