The Automatic 20 Position N-EVAP is an advanced blowdown evaporator combining classic blowdown technology with timed automation. The unit can run in automatic or manual mode due to the integration of a unique pneumatic system. The automatic mode removes samples from the heating medium when the designated time cycle has been completed. Samples can also be removed manually when the evaporation process is completed with the flip of a switch. The automatic concentration cycle reduces the likelihood of loss or damage to samples. A digital control system provides the operator with timed control of gas flow and bath temperature. A 9 position automatic instrument is also available for large glassware with outside diameters of 30-54 mm.