ISO 16750-4:2003 pdf download

ISO 16750-4:2003 pdf download.Road vehicles – Environmental
conditions and testing for electrical and electronic equipment—
Part 4: Climatic loads.
5.2.3 Requirement
The DUT shall take up its normal function at each temperature between Tmin and Tmax, i.e. the functional
status shall be Class A as defined in ISO 16750-1:2003, Clause 6.
5.3 Temperature cycling
5.3.1 General
Temperature cycling is based on IEC 60068-2-14.
5.3.2 Temperature cycle with specified change rate
5.3.2.1 Purpose
This test simulates varying temperatures during electrical operation of a system/component, for example during use at fast-changing ambient temperature. If the system/component is exposed to hot-soak temperatures (e.g. engine-mounted systems/components), an additional short temperature peak is added during the high temperature phase of the profile to ensure proper functioning during short temperature peaks. The electrical operation is switched off during phases of decreasing temperature in order to avoid electrical heat dissipation of the DUT which would inhibit the reaching of Tmin inside it. Failure mode is electrical malfunction during temperature change.
NOTE This test is not intended to be a life test.
5.3.2.2 Test
Perform the temperature cycling according to IEC 60068-2-14, Nb
Operate the DUT electrically (functional test) after the whole device has reached Tmin for the shortest possible
duration, in order to check that the device functions correctly. In addition, operate it electrically between
210 mm and 410 mm of the cycle (see Figure 2). Use Operating mode 3.2 in accordance with ISO 16750-1:2003, Clause 5 for the phases with electrical operation.
The changes in temperature shall be in accordance with Table 2. For tests including hot-soak temperature (TmaxHS), see Table 3.
Start the long period of electrical operation at 20 °C in order to allow possible condensation of humidity on the DUT. A permanent operation starting at Tmin would prevent this, owing to the electrical power dissipation.
Additional drying of the test chamber air is not permitted.
Perform 30 test cycles as specified.
5.3.2.3 Requirement
The functional status shall be Class A as defined in ISO 16750-1:2003, Clause 6.
5.3.3 Rapid change of temperature with specified transition duration
5.3.3.1 Purpose
This is an accelerated test which simulates a very high number of slow temperature cycles in the vehicle. The acceleration is possible due to a much higher temperature change rate and a bigger temperature change in one cycle in comparison to real vehicle stress. Failure modes are cracking of materials or seal failures caused by ageing and different temperature expansion coefficients. Because this test creates mechanical defects (cracks), electrical operation is not required.
5.3.3.2 Test
Perform the temperature cycling according to IEC 60068-2-14, Na.
Raise the temperature from Tmin to Tmax within 30 s. Keep the DUT, depending on its size and other properties, at each of these temperatures for 20 mm, 40 mm, 60 mm or 90 mm. Use Operating mode 1.1 in accordance with ISO 16750-1:2003, Clause 5. See Table 6 for the required number of cycles.
By agreement, this test may be performed during the development of a system/component with an opened housing or without a housing.
5.3.3.3 Requirement
The functional status shall be Class C as defined in ISO 16750-1:2003, Clause 6.
5.4 Ice water shock test
5.4.1 Purpose
This test simulates a thermal shock induced by cold water and is applicable to products in the splash areas of the vehicle. The purpose is to simulate cold water splashing over a hot system/component, as can happen when a vehicle is driven on wet roads in winter. Failure modes are mechanical cracking of materials or seal failures caused by different temperature expansion coefficients. An additional failure mode, not addressed in 5.3.3, is a loss of tightness and the intrusion of water into the system/component.
There are two alternative methods for performing the test (see 5.4.2 and 5.4.3).
5.4.2 Splash water method
5.4.2.1 Test
Heat the DUT in a hot air oven at Tmax for the specified holding time (‘h). Then use a jet to splash the DUT with cold water for 3 s.
If the DUT is splashed in the vehicle from only one direction, splash t from this direction only while it is in an as-installed position. If the equipment is splashed from various directions in the vehicle, then these directions shall be taken into account and a new DUT used for each splash direction. The width of the splash directed at the DUT shall always be greater than the width of the DUT. If a splashed DUT of considerable size proves too big for a single jet, arrange several jets in a row to produce a line of splash impact on the DUT. See Table 4.
See Figures 4, 5 and 6.