Note: Specification range and Operational Range, why they are different...
The Specification Range is the range at which the specific measurement is valid and accurate within our specifications.
The Operational Range relates to the temperature range that the unit will function. The primary limitations are display and battery.
The reason both are still valid is because it’s possible to take measurements beyond the operational range. For example, if you take the Kestrel Meter outside on a very cold day, you can measure temperatures beyond the operational range by waving the unit back and forth. Once the temperature of the display and batteries exceed the operational temperature, then the unit itself will no longer function.