GB 5170.18-1987 Basic parameter verification method of environmental test equipment for electrical and electronic products Temperature/humidity combined cycle test equipment GB5170.18-1987 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Environmental test equipment for electric and electronic products
Inspection methods for basic parameters ofenvironmental testlng equipments for electricand electroaic products
Composite temperature/numidity cyclictesting equipments
UDC 621.3.002.8- 79
GB 5170.1B—87
This standard specifies the inspection methods for basic parameters of the test equipment (hereinafter referred to as equipment) used in the temperature/humidity combination cycle test according to GB2423.34-86 "Basic environmental test methods for electric and electronic products Test Z/AD: Temperature/humidity combination cycle test method". When the temperature/humidity combination cycle test is conducted in the same test chamber (hereinafter referred to as the one-chamber method), it shall comply with all the provisions of this standard. When the temperature/humidity combination cycle test is conducted in two independent test chambers (hereinafter referred to as the two-chamber method), the damp heat test chamber shall comply with all the provisions of this standard; the low temperature test chamber shall comply with the provisions of GB5170.2-85 "Basic Parameter Verification Method of Environmental Test Equipment for Electrical and Electronic Products - Low Temperature Test Equipment".
This standard is used together with GB5170.1-85 "General Principles for Basic Parameter Verification Method of Environmental Test Equipment for Electrical and Electronic Products". 1 Verification Items
1.1 Temperature Error
1. 2 Relative humidity error
1.3 Heating and cooling characteristics
1.4 "T" Main instruments for verification of temperature difference between indoor and working space
2.1 Temperature test instrument
Use resistors or other similar sensors, and its time constant is not more than 20s. 1. Test instrument for indoor wall temperature, using surface temperature sensor.
2.2 Relative humidity test instrument
Use "wet table method" or other similar instruments, and its accuracy is ±1%. 2.3 Wind speed test instrument ||t t||Use anemometer, the induction should not be less than 10.05m/s3Verification method
3.1 Temperature and relative humidity error verification method3.1.1 This test is carried out according to the load conditions specified in GB5170.1 (or relevant standards). 3.1.2 Number and layout of test points
When testing temperature and humidity errors, the equipment's 1. working space is divided into three layers: upper, middle and lower, and a certain number of sensors are placed in the specified positions. National Bureau of Standards 1987-08-19 Approved
1988-05 01 Implementation
GB5170.18—87
Layout in the working space.
Temperature test points are represented by English letters A, B, C, D., and relative humidity test points are represented by letters A, B, C, D. Test point 0 is the geometric center of the working space. 3.1.2.1 When the volume of the upper working room is less than or equal to 1m3, there are 9 temperature test points and 3 relative humidity test points. The distance between the test point position and each side of the working room is 1/10 of the length of each side (when there is an air duct, it refers to the distance from the vent and return air outlet). When the equipment is equipped with a sample rack, the lower test point can be placed 10mm above the lower sample rack. The layout of temperature and humidity test points is shown in the figure 1. T+R
3.1.2.21 When the volume of the working room is greater than 11m\ and less than or equal to 10m\, there are 13 temperature test points and 4 relative humidity test points. The distance between the test point locations on each side of the working room is 10
of each side length (when there is an air duct, it refers to the distance from the air supply port and the air outlet). When the equipment is equipped with a sample rack or a sample cart, the lower test points can be placed 10mm above the lower sample rack or the sample cart. The layout of the temperature and humidity test points is shown in Figure 2.
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3.1.2.3 In order to ensure the temperature and humidity within the effective volume, it is allowed to increase the test points within the effective working space. 3.1.3 Verification steps
GB 5170.18-87
3.1.$.1 The one-chamber method test equipment cycles between high and low temperatures according to the procedures and requirements of Figure 2a of GB2423.34. And extend 3h in the final stage (25℃) as a cycle, see Figure 3. The two-chamber method wet heat test chamber cycles between high and low temperatures according to the procedures and requirements of Figure 2b, see Figure 4.3.1.3.2 The one-chamber method is tested in three constant stages, and the two-chamber method is tested in two constant stages. When the temperature of the indicator point in the equipment working space reaches the nominal value for the first time and stabilizes for 1h, within a period of 30min, the temperature of all points is tested once every 2min, for a total of 15 times. Then test once every 30min. Thereafter, test once every 1h until the end of the constant stage. The temperature and humidity error test record table refers to Table A1 in Appendix A (reference).
3.1.4 Data collation and result analysis
3.1.4.1 Correct the temperature value of each test point according to its respective correction value, and find out the relative humidity. 3.1,4.2 Analyze the corrected temperature and condensation values, where the maximum positive and negative deviations from the nominal value are defined as the temperature and cabinet relative humidity errors of the equipment at the nominal value. The temperature and relative humidity errors of the verification results shall comply with the relevant provisions of GB2423.34. 3.2 Verification method for heating and cooling characteristics
3.2.1 This test is carried out under load conditions
3.2.2 The test point is the geometric center point of the equipment working space 3.2.8 Verification steps
3.2.3.1 The test equipment of the one-box method cycles between high temperature and low temperature according to the specified procedures and requirements of Figure 3. The test equipment of the two-box method cycles between high temperature and low temperature according to the specified procedures and requirements of Figure 4. 3.2.8.2 During the heating and cooling stage, test the temperature and humidity values ​​of the center point once every 5 minutes. The test record table refers to Table A2 in Appendix A (reference).
3.2.4 Data and result analysis
3.2.4.1 Correct the tested temperature values ​​according to their respective correction values ​​and find out the relative humidity. 9.2.4.2 Draw the relative humidity and heating and cooling curves according to the above test results. The relative humidity and heating and cooling curves for the one-box method should comply with the provisions and requirements of Figure 3. … The box method should comply with the provisions and requirements of Figure 4. 3.3 Verification method of temperature difference between the inner wall and the working space of the working room 3.3.1 The test equipment of the box method should be subjected to this verification 3.3.2 This test is carried out under no-load conditions
3.3.3 Number and layout of test points
A total of test points are laid out at the geometric center of the working space of the equipment E and the geometric center of the six surfaces of the inner wall of the working room. The distance between the test point holes on the wall with lead holes or test holes is not less than 100mm 3.3.4 Verification steps
Within the adjustable temperature range of the equipment, the verification temperature is generally selected as the limit nominal temperature. After the temperature of the geometric center of the working space of the equipment I reaches the verification temperature for the first time and stabilizes for 1h (or other values ​​specified in relevant standards), the temperature values ​​of all points are tested once every 2-3in, for a total of times, and the arithmetic value is taken as the temperature value of each test point. The test record table refers to Table A3 in Appendix A (reference). ()
GB 5170-18-87
(Relative humidity is not controlled)
Time (b)
Selection limit
→Permissible limit
Optimum selection limit
Permissible limit
22628Time (h)
■Time tolerance of these points t5min
Cyclic procedure and requirements for box method verification
3.3.5 Data collation and result analysis
GB 5170.1B —87
202224
t012146
Figure 4 Cyclic procedure and requirements for three-box method verificationTime (h)
Time (h)
GB 6170.18-87
T = 273 +t
Tn= 273+
Where: T,——average thermodynamic temperature of the geometric center of the workspace, K; T,——average thermodynamic temperature of each test point on the inner wall of the workspace, K; 1,—average temperature of the geometric center of the workspace, CT,——average temperature of each test point on the inner wall of the workspace, C. Calculate the percentage of the difference between the inner wall of the workspace and the average thermodynamic temperature of the workspace, △T. AT
273k+t
The percentage of the average thermodynamic temperature difference between each test point and the geometric center of the workspace calculated according to formula (4) shall comply with GB2423.1-81 "Basic Environmental Test Procedures for Electrical and Electronic Products Test A: Low Temperature Test Method" Model name of the equipment being checked:
Model name of the calibration instrument:
Test environment conditions: temperature
Nominal value: temperature
Test results:
GB 6170.18-87
Appendix A
Example of test record form
(reference)
Temperature and humidity test record form
Table Al
Relative humidity
Relative humidity
Test period:
Testing personnel:
Model name of the equipment being checked:
Model name of the calibration instrument,
Test environment conditions, temperature
Nominal value, temperature
Control process
Test results:
GB 4170.18—B7
Table A2 Heating and cooling characteristics Temperature and humidity recording table accuracy
Relative humidity
Relative humidity
Relative humidity
Verification date:
Control process
Relative humidity
Verification personnel:
Model name of the equipment being tested:
Model name of the verification instrument;
Verification environment conditions: Temperature
Nominal value: Temperature
Winter study
Average temperature
Verification results:
Verification date:
Verification personnel:
GB 5170.18-87
Table A3 Workroom split and workspace temperature calibration record table accuracy
Relative humidity
What center point
As indoor wall test pointwwW.bzxz.Net
n(n=A, B, C, ..F)
B.1 Method for testing relative humidity by dry and wet table method GB 5170.18-87
Appendix B
Dry and wet decay method to test relative humidity
(reference)
. It is composed of two temperature sensing elements of the same model and equal accuracy, and the distance between the two temperature sensing elements is about 25mm. b. Wet bulb gauze uses No. 120 meteorological sandpaper, about 100mm long. Wet bulb water is distilled water or deionized water c. The water cup is preferably covered and filled with distilled water. The distance from the water surface in the water cup to the bottom of the wet bulb is about 30mm. d. When wrapping the wet bulb with gauze, wash your hands first, then wash the wet bulb with clean water, and then use the yarn on the gauze to wrap the gauze around the wet bulb without wrinkles, but the overlapping part should not exceed 1/4 of the circumference of the wet bulb. Do not tie it too tightly to avoid affecting water absorption, and cut off the excess yarn.
e: The wet bulb gauze should be kept clean, soft and moist, and generally changed once a week. , Read the difference between the dry and wet bulb thermometers, and use this difference to find the relative humidity value in the corresponding humidity lookup table corresponding to the dry bulb thermometer reading.
name, the relative humidity lookup table is determined according to the wind speed at each point in the equipment working space. The wind speed test is determined by the following method. B, 2 Wind speed test
, the number and layout of the test points are the same as the relative humidity test points. b. The wind speed test is carried out under no-load, and the anemometer probe is placed at the test point to measure the maximum wind speed at the point. Additional Notes:
This standard was proposed by the National Technical Committee for Environmental Conditions and Environmental Testing of Electrical and Electronic Products. This standard was drafted by the Working Group on Basic Parameter Verification Methods of Environmental Testing Equipment. The main drafter of this standard was Zhang Linzhen of Guangzhou Electrical Science Research Institute.
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