The measuring unit on the back of the tool os measuring the UV-emission between 250 and 410 nm. The result can be seen on the LCD display, unit of measure: millijoule/square-centimetre (mJ/cm²). The UV integratort is operated by a 3,6 V lithium battery, which can be found inside the unit. The special power-saving circuits ensure about 10 000 operating hours. The special filter-glasses absorb the visible and infrared range of the emission, so the measurement is done only in the necessary spectral range.