Open Combination and Hooded Combination Kjeldahl units have digestion and distillation components for nitrogen determination in one space-saving apparatus.  
 
Open Combination Kjeldahl units are supported by a sturdy, tubular steel framework, with the distillation apparatus mounted above the digestion portion. Models are available with the capacity to digest and distill up to 12 samples at a time. 
 
Hooded Combination Kjeldahl units enclose the distillation and digestion apparatus so that process heat may be contained and vented from the laboratory. The hood surrounding the apparatus includes three collars: one for remotely-located exhaust blower connection, one for acid fume exhaust manifold connection, and one for auxiliary-air blower inlet connection. Models are available that digest and distill up to 18 samples at one time. 
 
Kjeldahl units require a remote blower to exhaust fumes.