KNOX 2203 thermoreactor is constructed of durable materials with a vial capacity to perform up to 25 digestions simultaneously.The reactor is equipped with a user-selectable temperature setting to allow for COD and total phosphorus reactions at 150 ºC and also 105 ºC for total nitrogen analysis. To ensure the highest accuracy of digestion, a timer up to 120 minutes is incorporated. An audible alarm indicates when the incubating period is completed. The KNOX2203 is also equipped with an ON/OFF LED and a heating LED which advises the user when the selected temperature has been reached. For added safety, an auto-off feature is incorporated and an internal temperature sensor prevents over-heating of the samples. Knox 2203 Test Tube Heater 25 Vial (16 mm) Heating Block ideal for performing large numbers of tests and increasing productivity Factory Calibration provides a maintained accuracy of ±2oC Timer allows the reaction to take place unattended. After digestion, the shuts off automatically. Knox 2203