How far or from what distance can I measure to take a temperature measurement with an IR thermometer?
A. This depends on the optical capability of the IR thermometer. This is where the distance-to-spot ratio specification comes into play. Use the distance-to-spot ratio and the diameter of your target to determine the maximum distance you can be from the target. Most IR thermometers have a maximum measuring distance of approximately 100 feet (30 meters), depending on atmospheric conditions.
