- indoors or under cover in the absence of shakes, vibrations, vapors of aggressive liquids;
- ambient air temperature range, °С – from 10 until 35;
- relative air humidity, % – until 80;
- air pressure, mm Hg – 630-800;
- coefficient of non-sinusoidal of measurable voltage of alternating current should be no more than 8%;
- coefficient of pulsation of measurable voltage of direct current should be no more than 1%;
- distance from measurement unit RD140-MU for electrically conductive objects, which are grounded or under potential - at least 1 m;