BS EN 60068-2-1:2007

INTRODUCTION
1 Scope and object
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 Non heat-dissipating specimens
  4.4 Testing of heat-dissipating specimens
  4.5 Temperature monitoring
  4.6 Packaging
  4.7 Diagrammatic representations
5 Test description
  5.1 General
  5.2 Test Ab: Cold for non heat-dissipating specimens with
       gradual change of temperature
       5.2.1 Object
       5.2.2 General description
  5.3 Test Ad: Cold for heat-dissipating specimens with gradual
       change of temperature that are powered after initial
       temperature stabilization
       5.3.1 Object
       5.3.2 General description
  5.4 Test Ae: Cold 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
       5.4.3 Energizing the specimen
6 Test procedure
  6.1 Confirmation of performance
  6.2 Working space
  6.3 Thermal radiation
  6.4 Specimen with artificial cooling
  6.5 Mounting
  6.6 Severities
       6.6.1 Temperature
       6.6.2 Duration
  6.7 Preconditioning
  6.8 Initial measurements
  6.9 Conditioning
  6.10 Intermediate measurements
  6.11 Final temperature ramp
  6.12 Recovery
  6.13 Final measurements
7 Information to be given in the relevant specification
8 Information to be given in the test report
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications

Defines tests Aa, Ab, Ad which deal respectively with Cold for non-heat-dissipating specimen with sudden temperature change, with Cold for non-heat-dissipating specimen with gradual change of temperature.

This part of IEC 60068 deals with cold tests applicable to both non heat-dissipating and heat-dissipating specimens. For non heat-dissipating specimens, Tests Ab and Ad do not deviate essentially from earlier issues. Test Ae has been added primarily for testing equipment that requires being operational throughout the test, including the conditioning periods.

The object of the cold test is limited to the determination of the ability of components, equipment or other articles to be used, transported or stored at low temperature.

Cold tests cover by this standard 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.

The cold tests are subdivided as follows:

• Cold tests for non heat-dissipating specimens

  • with gradual change of temperature, Ab;

• Cold test for heat-dissipating specimens

  • with gradual change of temperature, Ad,

  • with gradual change of temperature, specimen powered throughout, Ae.

The procedures given in this standard are normally intended for specimens that achieve temperature stability during the performance of the test procedure.

Temperature chamber(s) are constructed and verified in accordance with specifications IEC 60068-3-5 and IEC 60068-3-7.

Further guidance for dry heat and cold tests can be found in IEC 60068-3-1 and general guidance in IEC 60068-1.