By the use of Thermo-Hygrometer it is possible to Read Temperature, rel. humidity of Air and EMC (UGL) form the measured room.
On the left scale the Temperature is indicated, on the right scale the rel. humidity is shown and at the cross point of the two needles the EMC / can be seen.
(See picture, where the temperature is 26°C, the rel. Humidity is 62% and the EMC is at 11%)