Using Communication Test Equipment in Cold Temperature (Winter) Environments

Winter overnight temperatures can get very low in certain regions. It is not recommended to leave test sets, unprotected from extremely low temperatures, in a truck/van/car. Check operational temperature on datasheet. Let the test set warm up.

Infrared image of the MTTplus tested at its -10C operational limit

Extreme temperatures require higher level of caution when it comes to test equipment. If you are using your equipment outdoors, ensure that you thoroughly check its compatibility with the current conditions. Some equipment may require additional time to warm up before use, while others may not function below a specific temperature or may deliver subpar performance. To effectively handle your test equipment, refer to its datasheet (specs) for guidance. Indoor use of test equipment can also be affected by the cold, particularly if it was stored outside unprotected (e.g., truck, car, van) or is a portable device that is frequently exposed to the outdoors.

Although modern test sets should be functional and accurate, withing the temperature ranges specified by manufacturers in their datasheets, users should not abuse or neglect them, and expect seamless operation at extreme temperatures. It is recommended to protect test equipment from overnight freezing temperatures.

Users must also exercise certain precautions before starting to test, such as letting the test set warm up to their operational temperature range, clean optical connectors, etc. Some meters may not generate enough internal heat to overcome the cold temperatures and warm themselves up, so they need to be brought into a warmer environment. It is also expected that the battery autonomy will be reduced to as much as 65% under freezing conditions, so plug the test set to AC as soon as possible.

Extremely cold temperatures may also make test cables (patch cords) stiff and their PVC jackets brittle, so one must be careful in handling them too, to avoid accidental damage, opens or shorts.

Of course, it is not just about the instruments, field technicians must stay warm and safe too. That includes wearing multiple layers of clothing, head cover and gloves, which may make using some test equipment extra challenging. Stay focus and double check settings and results.

Recommendations for Using Test Sets in Cold Weather

  • It is not recommended leaving test sets unprotected from extremely low temperatures, in a truck, van, or car outdoors.
  • Become familiar with your instruments' storage and operational temperature ranges, as specified by the manufacturers. For modular test sets, check both the test platform and the test module's specs and go with the most limited one.
  • Let the test set warm up before starting to test, so it gets into its specified operational range, for accurate measurement. Certain test sets and modules are capable of generating their own heat.
  • Do not bring test sets that have vents directly from cold into humid environments, as condensation can occur. The test set should be warmed up in a dry environment first.
  • Be mindful of water condensation or frost, which could be built on exposed optical connectors and affect optical measurements and transmission performance. 
  • Even if the batteries were fully charged, before storing the tester in a freezing environment, the battery management circuitry may report 0% charge after it is turned ON under battery power. Nonetheless, the test set should work correctly until the battery is depleted. The system will report the correct battery level once it recalibrates itself during the next charge session.
  • The screen (user interface) on meters with older LCD technology may become slow to respond under freezing conditions. Warm it up to their recommended operational temperature.