GB/T 10589-2008 English PDF (GBT10589-2008)

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GB/T 10589-2008: Specifications for low temperature test chambers
GB/T 10589-2008
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.040.10
N 61
Replacing GB/T 10589-1989
Specifications for low temperature test chambers
ISSUED ON: JUNE 30, 2008
IMPLEMENTED ON: JANUARY 01, 2009
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 5 
4 Conditions of use ... 7 
5 Technical requirements ... 8 
6 Test method ... 9 
7 Inspection rules ... 18 
8 Markings, packaging, storage ... 20 
Appendix A (Informative) Suspicious data identification method ... 22 
Appendix B (Informative) Evaluation of measurement uncertainty of
temperature variation ... 24 
Specifications for low temperature test chambers
1 Scope
This standard specifies the terms and definitions, conditions of use, technical
requirements, test methods, inspection rules, markings, packaging, storage
related to low temperature test chambers (referred to as test chambers").
This standard applies to test chambers that conduct low-temperature tests for
electrical, electronic and other products, parts, materials.
2 Normative references
The provisions in following documents become the provisions of this Standard
through reference in this Standard. For the dated references, the subsequent
amendments (excluding corrections) or revisions do not apply to this Standard;
however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable.
For undated references, the latest edition of the referenced document applies.
GB/T 191-2008 Packaging - Pictorial marking for handling of goods (ISO
780:1997, MOD)
GB 14048.1-2006 Low-voltage switchgear and controlgear - Part 1: General
rules (IEC 60947-1:2001, MOD)
JB/T 9512-1999 Climate environmental testing equipment and cabinet-
determination of sound power level of noise emitted
JJF 1059-1999 Evaluation and expression of uncertainty in measurement
3 Terms and definitions
The following terms and definitions apply to this standard.
3.1
Test chamber
An enclosed chamber and space the part of which can meet the specified
test conditions.
Temperature variation
After stabilization, the difference between the average temperature of the
center of the working space and the average temperature of other points in
the working space in any time interval.
3.10
Temperature extremes
After stabilization, the highest and lowest temperature reached in the
working space.
4 Conditions of use
4.1 Environmental conditions
a) Temperature 5 °C ~ 35 °C;
b) Relative humidity: Not more than 85%RH;
c) Atmospheric pressure 80 kPa ~ 106 kPa;
d) There is no strong vibration around;
e) No direct sunlight or direct radiation from other heat sources;
f) There is no strong airflow around: When the surrounding air needs to flow
forcibly, the airflow shall not be directly blown onto the chamber;
g) There is no strong electromagnetic field around;
h) There is no high concentration of dust and corrosive substances around.
4.2 Power supply conditions
a) AC voltage: 220V ± 22V or 380V ± 38V;
b) Frequency: 50 Hz ± 0.5 Hz.
4.3 Water supply conditions
Tap water or circulating water that meets the following conditions can be used;
a) Water temperature: Not higher than 30 °C;
b) Water pressure: 0.1 MPa ~ 0.3 MPa;
c) Water quality: In line with industrial water standards.
layer shall have sufficient thickness, to ensure that there shall be no
condensation in the test chamber when the test chamber is at low temperature
and the ambient temperature is 5 °C ~ 35 °C and the relative humidity is ≤ 85%.
5.2.3 The heating and cooling of heating and cooling devices shall not be
directly radiated on the test sample.
5.2.4 The working chamber shall be equipped with observation windows and
lighting devices.
5.2.5 The door of the chamber shall be well sealed; the sealing strip shall have
good resistance to high temperature aging and low temperature hardening.
5.2.6 The refrigeration system shall not have any defects such as air leakage,
water leakage and oil leakage.
5.2.7 There shall be a sample holder for placing or hanging test samples. The
sample holder shall have sufficient low temperature resistance.
5.2.8 It shall be provided with leading holes.
5.2.9 The appearance coating layer shall be flat and smooth, with uniform color;
there shall be exposed bottom, blistering, layering or scratches.
5.3 Safety and environmental protection requirements
5.3.1 Between the power supply terminal and the metal shell of the chamber
- Insulation resistance value shall meet the following requirements: cold state
resistance ≥ 2 MΩ, hot state resistance ≥ 1 MΩ;
- It shall be able to withstand a voltage withstand test of 50 Hz, 1500 V AC
voltage and a voltage application duration of 5 s.
5.3.2 The protective grounding terminal shall have a good electrical connection
with the test chamber's shell and be able to be easily and securely wired, which
shall meet the requirements of 7.1.9 in GB 14048.1-2006.
5.3.3 There shall be protection and alarm devices for over temperature, over
current, water shortage, etc.
5.3.4 The A-weighted sound power level of the complete machine noise shall
not be greater than 80 dB.
6 Test method
6.1 Main test instruments and devices
c) When the working chamber's volume is greater than 50 m3, the number of
temperature test points shall be appropriately increased.
6.3.2 Test procedure
6.3.2.1 Within the adjustable temperature range of the test chamber, select the
highest nominal temperature and the lowest nominal temperature.
6.3.2.2 Make the test chamber run according to the program of first low
temperature and then high temperature. After the temperature of the center
point of the working space reaches the test temperature and stabilizes for 2
hours, the temperature of all test points is tested once every 1 min within 30
minutes, a total of 30 tests are performed.
6.3.3 Data processing and test results
6.3.3.1 Correct the measured temperature data according to the correction
value of the test instrument.
6.3.3.2 Eliminate suspicious data (refer to Appendix A).
6.3.3.3 For the data measured in the constant temperature phase (i.e., the data
measured in 6.3.2.2), calculate the average temperature of 30 measured values
at each point according to formula (1):
Where:
- The average temperature, in degrees Celsius (°C);
Ti - The ith test value, in degrees Celsius (°C);
n - Number of measurements.
6.3.3.4 Calculate the temperature gradient according to formula (2):
Where:
ΔTj - Temperature gradient, in degrees Celsius (°C);
- The maximum value of the average temperature, in degrees Celsius
degrees Celsius (°C);
Ts - The temperature setting value, in degrees Celsius (°C).
6.3.3.8 All the above calculation results shall meet the requirements of Table 1.
6.3.3.9 According to actual needs, evaluate the uncertainty of the measurement
results (refer to Appendix B).
6.4 Method of testing the temperature difference between the inner wall of
the working chamber and the working space
6.4.1 Location and number of test points
6.4.1.1 Place one temperature sensor at the geometric center of the working
space, and one surface temperature sen...