GB/T 13475-2008Thermal insulation -- Determination of steady-state thermal transmission Properties -- Calibrated and guard hot box (English PDF)

Foreword

This standard is identical with ISO 8990:1994 (E) "insulation - Determination of steady-state thermal transmission properties - Calibrated and guarded hot box." this standard replaces GB/T 13475-1992 "building elements steady-state thermal transmission properties - Calibrated and guarded hot box." this standard compared with GB/T 13475-1992 main changes are as follows.

--- Standard topic made editorial changes;

--- Chapter 2 normative references have been modified;

--- Increasing the relevant provisions of the limitations and sources of error (see Section 1.6);

--- Increasing the relevant provisions of the plant design requirements (see Chapter 2);

--- Increasing the surface temperature of the relevant provisions of the device (see Chapter 2);

--- Measuring input power output power, fan heaters and the like thermopile balance accuracy has been revised (1992 version 5.7; this version 2.8);

--- Means the relevant provisions of performance evaluation and calibration have been revised and supplemented (see 2.9);

--- Revision of the relevant provisions of the specimen conditioning (1992 version 6.1; this version 3.2);

--- Delete the original standard in Appendix B, Appendix C and Appendix D (see the 1992 version of Appendix B, Appendix C and Appendix D);

--- Added Appendix B references;

--- Added Appendix NA.

Appendix A of this standard is a normative appendix, Appendix B and Appendix NA informative appendices.

Please note that some of the content of this standard may involve patents, the issuing authority of this standard should not bear the responsibility to identify these patents.

The standard proposed by China Building Materials Federation.

This standard by the National Standardization Technical Committee heat insulating material (SAC/TC191) centralized.

Introduction

Many situations require insulation and heat transfer properties of the insulating structure data, including to determine whether compliance with regulations and standards, design guidelines, materials Materials and building performance simulation research and verification test.

Many insulation materials and systems for heat transfer are conduction, convection and radiation of a complex combination. This International Standard describes the measurement method at a given temperature, the specimen is passed from one side to the other side of the total heat, it does not correspond to a single mode of heat transfer, so the test results can be used such thermal properties required of the occasion. However, the heat transfer properties of the specimen itself often and boundary conditions, the size of the specimen, the direction of heat transfer, temperature, Poor, air speed and relative humidity. Therefore, the test conditions must be expected to reproduce the practical application of the conditions, or in the assessment test the results measured under the conditions of whether meaningful.

It should also be remember that the determination of steady-state heat transfer and heat transfer characteristics of the nature of the specimen calculation is only able to explain or represent the actual product or system Performance measurement in order to consider the nature of material characterization, product or system feature is useful.

In addition, only a series of measurements from a plurality of samples of a plurality of test pieces having a sufficient reproducibility, the measured properties to generations

Table characteristics of the material, product or system.

Protection or calibration hot box design and operation is a complex task. Designers use of personnel and the device must have a complete biography Thermal background knowledge and experience in precision measurement technology.

There are many design calibration and guarded hot box apparatus in line with national standards in the world. Continued research and development of equipment and continually measure Technology improvements. The test structures may have a very big change, the conditions of the test requirements will be different, it is not necessary to limit Methods of measurement system and all measurements are limited to a single device it is wrong. Therefore, specify a particular design or size devices it is unrealistic.

Determination of steady heat transfer properties of the insulation Calibrated and guarded hot box

1 Overview