GB/T 5170.17-1987 Basic parameter verification method for environmental test equipment for electrical and electronic products Low temperature/low pressure/humid heat comprehensive sequential test equipment GB/T5170.17-1987 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Environmental testing equipment for electric and electronic products
Basic parameters verification methods
Combined sequential cold low air pressureand danp heat testing equipmentsUDC 621.3.002.6-79
GB 5170.17
This standard specifies the verification methods for basic parameters of environmental testing equipment (hereinafter referred to as equipment) used in the test according to GB2423.27-81 "Electrical and electronic products: Basic environmental testing procedures (Test Z/AMI) low temperature/low air pressure/humid heat continuous comprehensive test methods". This standard is used together with GB5170.1-85 "General rules for verification methods of basic parameters of environmental testing equipment for electric and electronic products". 1 Verification items
1.1 Cooling rate and temperature error
1. 2 Decompression rate and air pressure error
1.3 Heating time, pressure rise time and humidification rate1. 4 Temperature and relative coverage
1.5 Wind speed
2 Main instruments for verification
The error of the verification instrument should not be greater than one third of the allowable error of the measured parameter. 2.1 Temperature test instrument
Use platinum resistance or other similar sensors, and its time constant is not greater than 20s. 2.2 Air pressure test instrument
Use standard mercury pressure gauge or other similar barometer (meter). 2.3 Relative humidity test instrument
Use ten wet bulb hygrometer or other similar instruments. 2.4 Wind speed test instrument
Use various anemometers, and its induction is not less than 0.05m/s. 3 Verification method
The continuous comprehensive verification program curve is shown in Figure 1.
3.1 Cooling rate and temperature error verification method 3.1.1 This test should be carried out under the load conditions specified in GB5170.1 (or other provisions of relevant standards). 8.1.2 Temperature test points and layout positions
When testing cooling rate and temperature error. -Generally, the working space of the equipment is divided into upper, middle and lower (or front, middle and back) layers, and the National Bureau of Standards approved it on August 19, 1987 and implemented it on May 1, 1988. A certain number of sensors are placed in the specified positions. Relative to 30℃ or room pressure drop rate is not more than i/min (whichever is higher) 0-5℃ T (rated low temperature value) positive atmospheric pressure P (verification low atmospheric pressure) record the initial temperature and pressure drop rate GB 5170.1187
The temperature curve of the load surface
The pressure reduction rate does not exceed
10kPa/min
The pressure reduction rate is
- 30 -
The accuracy and
difference test
Start as wet, the rate
is based on the corrosion load
415-30
and the temperature is increased
and the pressure is increased
and the test
Figure 1 The calibration procedure diagram of the low temperature/low pressure/heat leakage comprehensive sequential test equipment
There is condensation
The temperature curve of the load surface
Accuracy and
Relative range test
3.1.2 .1 When the equipment volume is small, 1 or 11m\, there are 9 temperature test points. The distance between the test point position and the obstacle in the working room is 1/10 of the length of each side of the working room (the diameter of the working room for circular equipment), and the minimum distance shall not be less than 50mm. When the equipment is equipped with a sample rack, the lower test point can be arranged 10mm above the bottom sample rack. The test point layout is shown in Figure 2. Square shadow equipment:
Circular equipment (taking cylindrical horizontal equipment as an example): Front
GB5170.17-87
3.1.2.2 Setting When the equipment volume is greater than 1m2 and less than or equal to 10m2, there are 13 temperature test points, and the distance between the test point position and the inner wall of the T working room is 1/10 of the length of each side of the working room (1 working room diameter for circular equipment) (when there is an air duct, it refers to the distance between the air supply and return air outlets). When the equipment is equipped with a sample rack, the lower test points can be placed 10mm above the bottom sample rack. The test point layout is shown in Figure 3. Square equipment:
Circular equipment (taking a circular horizontal equipment as an example): front layer
back layer,
3.1. 2.3 When the volume of the equipment is greater than 10m3, there are 21 temperature test points, and the distance between the test points and the working room is 1/10 of the length of each side of the working room (the diameter of the working room for circular equipment) (when there is a duct, it refers to the distance from the air supply and return outlets), but the maximum distance shall not exceed 500mm. When the equipment is equipped with a sample car, the lower test points can be placed 10mm above the bottom sample car. The test point layout is shown in Figure 4. Square equipment:
Circular equipment (taking circular horizontal equipment as an example):
GB 5170.17-87
3.1.2.4 In order to ensure the temperature and humidity requirements, it is allowed to increase the test points in the effective space. 3.1.3 Verification steps
Within the adjustable temperature range of the equipment, the verification temperature is generally selected as the limit nominal temperature or the representative nominal temperature point specified in GB2423.1-81 "Basic Environmental Test Procedure for Electrical and Electronic Products Test A, Low Temperature Test Method". During the cooling process of the equipment, record the temperature value of the indicating point every 5 minutes. Refer to Appendix A (reference) Table A1 for the test record table. When the indicating point temperature drops to the low temperature setting value, it is stable for 1 hour, and then the temperature error of the equipment working space is tested. During the test, record the temperature values ​​of all points every 2 minutes, and test 15 times in 30 minutes. Refer to Appendix A (reference) Table A2 for the test record table. 3.1.4 Data collation and result analysis
8.1.4,1 Cooling rate
Calculate the average cooling rate within 5 minutes during cooling according to the following formula: IAT
Where: r——average cooling rate, c/min, AT
——temperature difference every 5 minutes, °C.
3.1.4.2 Temperature error
Correct the temperature value of each test point according to the correction value of the test instrument, analyze the corrected test data, and the maximum negative deviation from the nominal temperature is defined as the temperature error of the equipment at the nominal temperature. The verification results should comply with the relevant provisions of GB2423.27. 3.2 Decompression rate and pressure error verification method 3.2.1 This test should be carried out under the load conditions specified in GB 5170.1 (or other provisions of relevant standards). 3.2.2 The test point is the pressure point of the equipment
3.2.8 Verification steps
GB 5170.17-87
Maintain the verification low temperature conditions specified in Section 3.1.3 of this standard, and within the adjustable range of the equipment low pressure, select the limit nominal pressure or the representative nominal pressure specified in GB2423.2181 "Basic Environmental Test Procedures for Electrical Products Test M: Low Pressure Test Method" as the verification value. During the equipment decompression process. Record the time it takes for the equipment to drop from normal atmosphere to the verification low pressure. When the air pressure at the indicating point drops to the low pressure setting value, stabilize for 30 minutes, and then test the air pressure of the working space of the equipment. During the test, record the air pressure value every 2 minutes, and test 15 times in 30 minutes. Refer to Appendix A (reference) Table A3 for the test record table. 3.2.4 Data collation and result analysis
3.2.4.1 Pressure reduction rate
Calculate the average rate of change during pressure reduction according to the following formula; P,- P
Where: ---average rate of change of pressure reduction, kPa/minP-normal pressure, kPaz
P-calibration air pressure, kPa
Decompression time, min.
3.2.4.2 Air pressure error
Correct the air pressure value of the indicating point according to the test instrument, temperature and gravity correction values, analyze the corrected test data, and define the maximum positive and negative deviations from the nominal air pressure as the air pressure error of the equipment at the nominal air pressure. The test results shall comply with the relevant provisions of GB2423.27. 3.3 Test methods for heating time, pressure rise time and humidification rate 3.9.1 This test shall be carried out under the load conditions specified in GB5170.1 (or in accordance with other provisions of relevant standards). 8.3.2 There are two temperature test points, one temperature sensor is placed at the geometric center of the equipment, and the other surface temperature sensor is placed at the load surface.
The air pressure test point is the pressure point of the equipment.
3.3.3 Verification steps and result analysis
Maintain the low pressure conditions specified in Section 3.2.3 of this standard, so that the temperature of the equipment working space rises evenly. When it rises to 30C or the indoor temperature (whichever is higher), record the time it takes for the temperature at the indicating point to rise from the verification low temperature to the set temperature, which is the heating time of the equipment. Humidify while the temperature at the indicating point rises, and observe the frost on the load surface. Record the temperature of the load surface. When the surface temperature of the load reaches between 0 and 5℃ and the surface begins to defrost, make the air pressure in the equipment working space rise to normal atmospheric pressure at a high and uniform speed, and record the time it takes for the air pressure at the indicating point to rise from the verification low pressure to normal atmospheric pressure, which is the pressure rise time of the equipment. The verification results should comply with the relevant provisions of GB2423.27. 3.4 Temperature and relative humidity verification method
3.4.1 This test is carried out under the load conditions specified in GB5170.1 (or other provisions of relevant standards). 3.4.2 The temperature and humidity test points are all geometric points of the equipment. 3.4.3 Verification steps and result analysiswwW.bzxz.Net
When the air pressure at the indicating point rises to the positive atmospheric pressure and the temperature at the indicating point rises to 30°C or the indoor temperature (whichever is higher), keep it for 1 hour, and record the temperature and humidity values ​​of the indicating point every 5 minutes, and observe the condensation on the load. The verification results should comply with the relevant provisions of GB2423.27. 3.5 Wind speed verification method
3.5.1 This test is carried out under no-load and room temperature conditions. 3.5.2 Number and layout of test points
According to the size of the equipment, the number and layout of wind speed test points should be the same as those of temperature test points. 3.5.3 Verification steps
Place the anemometer at the test point, test the wind speed at each point in any direction, and take the maximum value as the wind speed at each test point. Refer to Appendix A (reference) Table A4 for test records.
8. Data collation and result analysis
GB 5170. 17-11
Calculate the average wind speed in the equipment working room according to the following formula =
Where: "Average wind speed in the equipment working room, ms; V—wind speed at each test point, m/s
—number of test points.
The verification results should comply with the relevant provisions of GB24231. Model name of the equipment under test:
Model name of the calibration instrument:
Calibration environment conditions, temperature
Calibration temperature:
Test time
Calibration date:
Calibrator:
Model name of the equipment under test:
Model name of the calibration instrument:
Calibration environment conditions: temperature
Calibration temperature:
Test point
Calibration result:
Calibration date:
Calibrator:
GB5170.17--87
Appendix A
Test record example
(reference)
Cooling rate test record sheet
Relative humidity
Test temperature|| tt||Temperature change within 5tain
Table A2 Temperature error test record
Relative humidity
Fast average cooling rate
Model name of the equipment under test:
Model name of the calibration instrument:
Calibration environment conditions: temperature
Calibration air pressure value:
Test time
Barometer reading
Calibration result:
Calibration date:
Calibrator:
Model name of the equipment under test
Model name of the calibration instrument,
Calibration environment conditions: temperature
Test point
Calibration result:
Calibration date:
Calibrator:
Additional instructions:
GB 5170.17-87
Table A3 Air pressure error test record
Relative intensities
Table A4 Wind speed test record
Relative humidity
This standard is proposed by the National Technical Committee for Environmental Conditions and Environmental Testing for Electrical and Electronic Products. This standard is drafted by the Working Group on Basic Parameter Verification Methods for Comprehensive Environmental Testing Equipment. The main drafter of this standard is Fu Wenru.
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