The equipment has a very casted top with room for heating 40 digestion tubes of 75 ml. Each. Heating elements are speared uniformally so that the entire casted top, and thus the tubes, attain the same temperature throughout. Temperature is controlled by Digital Microprocessor PID Temp. Controller. The gap between the elements and outer M.S. painted wall is fitted with high grade mineral wool to avoid thermal loss. To work on 220 / 230 volts A.C. Supply 40 tubes dia 24 mm.