The 12 position N-EVAP nitrogen evaporator (cat# 11155) is a compact unit that allows for up to 12 samples to be evaporated simultaneously. At each individual sample position the gas flow can be controlled via a precision needle valve. This is ideal for the simultaneous evaporation of samples with varying evaporation end points. The sample tray has a spring tensioner which allows any test tube between 10-30 mm to be processed without any modifications to the instrument. An optional small sample holder allows samples with an outside diameter of 5-16 mm to be processed.