AS 1099.3.1-1980

1 - AS 1099.3.1-1980 BASIC ENVIRONMENTAL TESTING PROCEDURES FOR ELECTROTECHNOLOGY - BACKGROUND INFORMATION - TESTS A AND B; COLD
1 - CONTENTS
1 - FOREWORD
2 - SPECIFICATION
2 - 1 SCOPE AND APPLICATION.
2 - 2 REFERENCE AMBIENT CONDITIONS.
2 - 3 DEVICES WITHOUT HEAT-DISSIPATION.
2 - 4 DEVICES WITH HEAT-DISSIPATION.
2 - 5 AMBIENT TEMPERATURE.
2 - 6 SURFACE TEMPERATURES.
2 - 7 MECHANISMS OF HEAT TRANSFER.
2 - 7.1 Convection.
3 - 7.2 Thermal Radiation.
3 - 7.3 Thermal Conduction.
4 - 7.4 Forced Air Circulation.
4 - 8 TEST CHAMBERS.
4 - 8.1 General.
5 - 8.2 Methods of Achieving the Required Conditions in the Test Chamber.
5 - 9 MEASUREMENTS.
5 - 9.1 Temperature.
5 - 9.2 Air Velocity.
5 - 9.3 Emissivity Coefficient.
6 - APPENDIX A - GENERAL BLOCK DIAGRAM, COLD AND DRY HEAT TESTS
7 - APPENDIX B - EFFECT OF AIRFLOW ON CHAMBER CONDITIONS AND ON SURFACE TEMPERATURES OF TEST SPECIMENS
7 - B1 CALCULATION OF THE EFFECT OF AIRFLOW ON SPECIMEN TEMPERATURE AND ON TEMPERATURE GRADIENT IN THE CHAMBER.
7 - B1.1 Specimen Temperature.
7 - B1.2 Gradient Between Incoming and Outgoing Air.
11 - APPENDIX C - EFFECTS OF SIZE OF CHAMBER ON SURFACE TEMPERATURE OF A SPECIMEN WHEN NO FORCED AIR CIRCULATION IS USED
13 - APPENDIX D - EFFECT OF SPECIMEN EMISSIVITY COEFFICIENT ON TEMPERATURE RISE
14 - APPENDIX E - MEASUREMENT OF EMISSIVITY COEFFICIENT
14 - E1 INTRODUCTION.
14 - E2 RADIATION THEORY.
15 - E3 PRACTICAL APPLICATIONS OF RADIATION THEORY.
15 - E3.1 Error Magnitudes.
15 - E3.2 Wavelength Range and Energy Distribution of the Temperature Radiation.
15 - E3.3 Total Radiation.
16 - E4 METHODS OF MEASUREMENTS OF EMISSIVITY COEFFICIENT.
16 - E4.1 General.
16 - E4.2 Measurements of the Value of the Emissivity Coefficient.
17 - E4.3 Check to Ensure that a Minimum Value of Emissivity Coefficient is Exceeded.
17 - E5 EMISSIVITY COEFFICIENT VALUES.
17 - E6 METHODS OF INCREASING THE EMISSIVITY OF TEST CHAMBER WALLS.
17 - E6.1 Coatings and Other Surface Treatments.
17 - E6.2 Mechanical Structures.
21 - APPENDIX F - HEAT TRANSFER CALCULATIONS AND NOMOGRAMS
21 - F1 NOMENCLATURE.
21 - F2 HEAT TRANSFER BY RADIATION.
21 - F3 HEAT TRANSFER BY RADIATION AND CONVECTION.
21 - F3.1 Heat Transfer.
22 - F3.2 Nomograms.
22 - F4 CORRELATION NOMOGRAMS USED IN TEST A AND TEST B.
27 - APPENDIX G - EFFECT OF WIRE TERMINATION DIMENSIONS AND MATERIAL ON SURFACE TEMPERATURE OF A COMPONENT
28 - APPENDIX H - THERMAL CONDUCTIVITIES OF COMMON MATERIALS
29 - APPENDIX J - MEASUREMENT OF TEMPERATURE
29 - J1 GENERAL.
29 - J2 METHODS USING COLOUR CHANGING OR MELTING EFFECTS.
30 - J3 METHODS USING INFRARED SENSORS.
31 - APPENDIX K - MEASUREMENT OF AIR VELOCITY

This standard gives guidance on the performance of Test A, cold and Test B, Dry Heat. It gives reasons for the selection of an appropriate test procedure, describes the design of test equipment and provides test methods for various test parameters.

This Section gives guidance on the performance of Test A, cold and Test B, Dry Heat. It gives reasons for the selection of an appropriate test procedure, describes the design of test equipment and provides test methods for various test parameters.The performance of components and equipments is influenced and limited by their internal temperatures which depend on the external ambient conditions and on the heat generated within the device itself. Whenever temperature gradients exist in the system formed by a device and its surroundings, a process of heat transfer will ensue.The tests cover cold and dry heat testing, with both sudden and gradual change of the temperature, and of non-heat-dissipating and heat-dissipating specimens (the latter with or without artificial cooling).The use of test chambers with and without forced air circulation is covered as appropriate. A general block diagram of the total procedure is given in Appendix A.

Under Revision see DR 02486 CP