The ‘Operating Range’ of a device is simply a measure of the ‘Temperature Range’ in which the electronics can handle. For a handheld like the P125 Pocketherm Folding Thermometer, this is often quoted as being ‘-20 to +50°C’ , which is about the maximum ‘Operating Range’ for a Thermometer that is hand-held. Use of the Thermometer outside of this range would be possible, but would require the use of specialised components which can withstand higher and lower extremes of temperature.
Any Thermometer that has a Probe connected to it, can cope with inputs that far exceed the ‘Operating Range’ because the instrument itself is not subjected to the same extremes of temperature. It is the Probe that is making the contact itself and which has to be built to withstand the extreme temperature.
In the case of the P125 Pocketherm Folding Thermometer, or any Thermometer with a fixed probe, it might seem seem a little odd having the ‘Measurement Range’ greater than the ‘Operating Range’. But in the case of the P125 Pocketherm it would be possible to insert the probe into a product that was very cold, so long as the instrument and the hand holding it did not drop below -20°C. However, in the main application for the Pocketherm Folding Thermometer – Food – this extreme cold is very unlikely, although may be possible to probe a frozen product that could be below -20°C.