The FoxBox is a field portable integrated oxygen and carbon dioxide analysis instrument that includes a variable pump and mass flow meter (range 20 - 2000 ml/minute). All of these instruments are integrated into a small (10"x10.5"x7"), light (8 lbs.), compact, hermetically sealed, dustproof, waterproof field rugged case. The Foxbox is also avaliable as an oxygen only configuration for applications that do not require carbon dioxide measurements.