Thermal measuring (thermal checking) carry out by difference of the temperature between internal and outdoors air, no less then 15 C.  Then higher is the temperature difference, then more accurate the results of thermal imaging examinations are (and if the temperature is +15 ° C in the house, then the outside temperature should not be higher than 0 ° C).Before checking, the place  heating should be continuous and uniform for 1-2 days.

Surface checking should not be n the area of direct and reflected solar radiation.Thermal cheking better carry out in cloudy weather (in the absence of sunlight) or before sunrise or after sunset.

It is recommended that window and door openings in the examined object be kept in a fixed position for 12 hours before and during the measurement process (windows and doors should be closed).

Surfaces of controlled areas must be freed from objects that impede thermal imaging inspection. The room should not be cluttered; flower pots and other items should be removed from the window sills.