III. what is the comprehensive test? III. general inspection standard for comprehensive test

Date：2021-07-29 11:38:00Views：3078

3. Comprehensive test refers to the test that integrates the three environmental stresses of temperature, humidity and vibration. This test is used to assess the adaptability of products to transportation and use in the environment of temperature, humidity and vibration. Compared with the effect of single factor, it can more truly reflect the adaptability of electrical and electronic products to the changes of temperature, humidity and vibration compound environment in the process of transportation and actual use, and expose the defects of products. It is an indispensable important test means in the whole process of new product development, prototype test and product qualification test. There are also impact and collision. The specific matching test depends on the customer's requirements.

Temperature vibration test (two comprehensive tests: vibration steam temperature, temperature steam humidity and vibration steam humidity; three comprehensive tests: vibration steam temperature and humidity) is a test condition realized by a test equipment composed of a constant temperature and humidity test chamber or a rapid temperature rise and fall test chamber and a vibration table. Three comprehensive tests shall be conducted simultaneously to the influence of temperature, humidity and vibration on the product. Applying a single environmental stress to the product can trigger the failure of the product, so applying three different environmental stresses to the product can easily get 3-5 times the acceleration effect. At the same time, by integrating different environmental stresses, faults that cannot occur when a single stress is applied can be excited.

During the comprehensive test of simultaneous application of temperature, humidity and vibration, from the mechanism of fault occurrence, the internal part of the product undergoing temperature cycle expands and contracts due to the difference of material expansion coefficient, and loosens at the joint. At this time, if humidity is applied, moisture will invade from the gap, reducing the friction coefficient at the joint and joint. When the vibration stress is applied again, the resonance phenomenon of the product will occur relative to the specific frequency. In this way, through the repeated processes of movement, moisture absorption, freezing and resonance, it is possible to appear new failure modes (caused by the greatly accelerated single factor failure mode and the combined superposition effect of three factors).

III. comprehensive test: temperature + humidity + vibration / shock / collision

Temperature range: - 70 ℃ ~ + 180 ℃

Humidity range: 10% RH ~ 98% RH

Temperature change rate: ≤ 20 ℃ / min

Vibration thrust: 2200kgf, 5500kgf

Vibration displacement: ≤ 90mm

Vibration frequency: ≤ 2700hz

Vibration acceleration: ≤ 100g

Impact acceleration: ≤ 200g

Pulse width: 0.5ms ~ 25ms

Collision frequency: ≤ 120 times / min

III. detection scope of comprehensive test:Auto parts, fasteners, seals, electronic products, etc.

III. comprehensive test and detection standard:

1. GB / T 2423.25-2008 environmental testing of electric and electronic products Part 2: Test methods Test Z / am: low temperature / low pressure comprehensive test

2. GB / T 2423.26-2008 environmental testing of electric and electronic products Part 2: Test methods Test Z / BM: high temperature / low pressure comprehensive test

3. GB / T 2423.27-2005 environmental testing of electric and electronic products Part 2: Test methods Test Z / AMD: low temperature / low pressure / damp heat continuous comprehensive test

4. GB / T 2423.35-2005z/afc: low temperature / vibration (sinusoidal) comprehensive test of heat dissipation and non heat dissipation test samples

5. GB / T 2423.35-2019 environmental testing Part 2: tests and guidelines comprehensive tests of climate (temperature, humidity) and dynamics (vibration and impact)

6. GB / T 2423.36-2005 environmental testing of electric and electronic products Part 2: Test methods Test Z / BFE, high temperature / vibration (sinusoidal) comprehensive test of heat dissipation and non heat dissipation test samples

7. GB / T 2424.15-2008 environmental testing of electric and electronic products - Part 3: Guide for comprehensive temperature / low pressure test

8. GB / T 2424.22-1986 basic environmental test procedures for electrical and electronic products - Guide for comprehensive temperature (low temperature, high temperature) and vibration (sinusoidal) tests

9. GB / T 5170.19-2018 test methods for environmental test equipment Part 19: temperature and vibration (sinusoidal) comprehensive test equipment

10. GB / T 12085.5-2010 environmental test methods for optics and optical instruments Part 5: comprehensive test at low temperature and low pressure

III. purpose and significance of comprehensive test

III. The comprehensive environmental test chamber mainly provides the temperature and humidity change environment for scientific research and production units such as aerospace, aviation, petroleum, chemical industry, electronics and communication. At the same time, the electrical vibration stress can be applied to the test object according to the specified cycle in the test chamber for the user to conduct the temperature, humidity and vibration comprehensive stress screening test on the whole machine (or components), electrical appliances, instruments and materials, So as to assess the adaptability of the test object or evaluate the behavior of the test object. Compared with the effect of single factor, it can more truly reflect the adaptability of electrical and electronic products to the changes of temperature, humidity and vibration compound environment in the process of transportation and actual use, and expose the defects of products. It is an indispensable important test means in the whole process of new product development, prototype test and product qualification test.