Meeting & Exceeding Standards: Temperature Extremes & Shock

Posted on

The military created MIL-STD-810G to establish test methods for determining the resistance of equipment against the effects of rugged environments. Several tests relate to a device’s ability to withstand temperature extremes and temperature shock.

High Temperature Testing

Storage: For equipment stored at high temperatures
Equipment is placed in the test chamber according to its storage configuration. Temperature is adjusted in cycles or set for constant exposure depending on expected storage environment. A minimum of seven 24-hour cycles are completed or a constant temperature is maintained for at least two hours

Operation: For equipment expected to operate at high temperatures
Equipment is placed in the test chamber according to its operational configuration. A minimum of three cycles are completed or a constant temperature is maintained for at least two hours.

Tactical-Standby to Operational: For equipment likely to be exposed to non-operational temperatures and expected to perform when returned to operational temperature
Equipment is placed in the test chamber according to its tactical configuration. Temperature is raised to expected maximum non-operating temperature and maintained for two hours. Temperature is reduced to maximum operational temperature, and equipment is tested for operation.

Low Temperature Testing

Storage: For equipment stored at low temperatures
Equipment is placed in the test chamber according to its storage configuration. Temperature is reduced at rates not exceeding 3°C/min or 5°F/min until reaching minimum storage temperature and maintained for a length of time dependent on storage conditions.

Operation: For equipment expected to operate at low temperatures
Equipment is placed in the test chamber according to its operational configuration. Temperature is reduced at rates not exceeding 3°C/min or 5°F/min to minimum storage temperature and maintained for at least two hours.

Manipulation: For equipment that must be set up and disassembled by personnel wearing heavy, cold-weather clothing
Equipment undergoes Operation testing. For a walk-in test chamber, heavy clothed personnel assemble and disassemble the equipment. For smaller test chambers, the equipment is set up and broken down through access holes by personnel wearing heavy gloves.

Temperature Shock

One-Way Shock: For equipment likely to be exposed to thermal shock in one direction (high-to-low temperature or vice-versa)
Equipment is placed in the test chamber according to its logistic configuration. Temperature is adjusted to increase or decrease at rates not exceeding 3°C/min or 5°F/min to extreme temperature and stabilized. Equipment is transferred in less than one minute to a secondary chamber set at a temperature to produce thermal shock and stabilized for a period dependent on expected environmental conditions.

Single Cycle Shock: For equipment likely to be exposed to one thermal shock cycle in both directions (both high-to-low and low-to-high)
Testing is the same as One-Way Shock except after stabilization in the second environment, the equipment is returned to the original test chamber to produce shock in the other direction.

Multi-Cycle Shock: For equipment likely to be exposed to multiple thermal shock cycles.
Testing is the same as Single Cycle Shock except equipment is transferred between chambers for at least three cycles.

Controlled Ambient Temperature Shock: For equipment likely to be exposed to shocks due to controlled ambient conditions
Equipment undergoes the same testing as Single and Multi-Cycle Shock expect temperatures are set to ambient conditions.

Sealevel Environmental Testing

Sealevel creates custom solutions for equipment operating in extreme temperatures. Sealevel performs rigorous in-house testing and utilizes various test equipment including a walk-in thermal chamber capable of performing thermal shocks and soaks.