GB/T 2424.5-2021Environmental testing - Part 3: Supporting documentation and guidance - Confirmation of the performance of temperature chambers (English PDF)

4.1 of 2006 Edition);

c) Delete "temperature performance measurement" (see 4.5 of 2006 Edition);

d) Add "measurement method" (see 4.5 of this Edition);

e) Adjust the content of Clause 5 of the 2006 edition to 4.6 of this Edition.

This Document used the translation method to equivalently adopt IEC 60068-3-5:2018

Environmental Testing - Part 3-5: Supporting Documentation and Guidance - Confirmation of

the Performance of Temperature Chambers.

The Chinese documents that have consistent correspondence with the international documents

cited in this document are as follows:

--- GB/T 2424.7-2006 Environmental tests for electric and electronic products -

Measurements in temperature chambers for tests A and tests B (with load) (IEC 60068-

3-7:2001, IDT);

--- GB/T 2424.27-2013 Environmental testing - Supporting documentation and guidance -

Calculation of uncertainty of conditions in climatic test chambers (IEC 60068-3-11:2007,

IDT).

This Document made the following editorial modifications:

--- Change the standard name into Environmental Testing - Part 3: Supporting

Documentation and Guidance - Confirmation of the Performance of Temperature

Chambers.

--- Add the Annex "The components of GB/T 2424" (see Annex NA).

Environmental Testing - Part 3: Supporting Documentation

and Guidance - Confirmation of the Performance of

Temperature Chambers

4.1 Test area environment

The environment around a temperature test chamber may influence the conditions inside the

test chamber.

The confirmation of performance of temperature chambers should be carried out under standard

atmospheric conditions specified in IEC 60068-1.

4.2 Temperature measurement system

The uncertainty of measurement of the output of the measurement system should be determined

by calibration of the system, traceable to international standards (see ISO 10012).

The temperature sensors may be either calibrated platinum resistors or a thermocouple. The

thermal response time of the sensors shall be within a minimum of 10s and a maximum of 40s

for 50 % of response. It is preferred that the thermal response time of the entire measurement

system to be less than 40s. The use of sensors that are compliant to IEC 60584-1 tolerance class

4.3 Temperature chamber test specimens

All measurements described in 4.5 are performed with an empty working space. For measuring

with test specimens (with or without heat dissipation), see IEC 60068-3-7.

4.4 Specified location of temperature sensors in working space

Temperature measuring sensors are located in each corner and in the center of the working

space (see Figure 3, minimum 9 sensors). For temperature chambers over 2 000 l, additional

sensors should be located in front of the center of each wall (see Figure 4, minimum 15 sensors).

The measuring system is to be arranged in such a way that the temperature distribution of the

empty test chamber will not be affected.

For a large capacity chamber, there may be a significant difference between the temperature

control sensor(s) and the temperature at the center of the working space. It may be necessary to

adjust the temperature setting to achieve the necessary tolerance.

For confirmation monitoring, data should be recorded at least once a minute. The device used

for recording data from the chamber monitoring sensors should be independent of the chamber

control system.

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