Profile: Advanced Instruments Inc specializes in manufacturing analytical instrumentation specializing in the gas detection measurement of percent, ppm, ppb, and trace levels of oxygen. The GPR-2000 oxygen analyzer is a galvanic sensor capable of oxygen analysis from 0.05 to 100 percent. It operates on rechargeable battery for 60 days after an overnight charge. It features optional panel mounted flow meter (M suffix), coalescing filter (C suffix) and carrying case.