One important design specification was the need for an extended ambient temperature range of -35 to 80 °C (-30 to 175°F) for the new rugged QuantumX modules.
Testing that the modules could function properly at these extreme temperatures was undertaken with climate chambers that examined the influence of rapidly cycling temperature changes and humidity on the units. These tests ensured continued functionality in these environmental conditions whether in transit, being stored or while in operation.
Thermal shock tests were performed to determine the unit’s ability to withstand sudden changes in temperature. These are the most severe of all the temperature related tests as they involve rapidly changing the rate of temperature change. The modules are designed for an operational rate change of 30°C per minute. The tests are particularly critical since modules may be used in vehicle winter tests where they can be completely frozen with all power off and subsequently warmed up once the power has been resupplied.
HBM’s engineers simulate real-life conditions by exposing the module to -40 °C for three hours and then to 85°C within a short period. The temperature remains at this level for a further three hours before being restored to ambient room temperature so that the dew point is passed, ensuring any water condenses to check the effect on the module. The test is repeated a minimum of ten times.