Chemical digestion of samples is required for the photometric determination of COD, TOC, total chromium, total phosphate and total nitrogen. The required temperatures and reaction time can be selected by using the membrane keypad of the reactor RD 125. The unit works at three different temperatures (100 / 120 / 150 °C) and three pre-set reaction times (30 / 60 / 120 minutes). When digestion is complete, the reactor automatically switches off and gives a corresponding LED indication with short beep alarm. The RD 125 reactor is fitted with 24 holes for 16 mm diameter vials.