Palm O2 Nitrox analyzers provide a very easy way to verify oxygen in diving applications. These inexpensive gas analyzers measure and display the concentration of oxygen in compressed breathing air tanks intended for scuba diving, for personnel safety, area monitoring, O2 deficiency in confined spaces, checking breathing air tanks and confirming the O2 levels prior to welding. The devices utilize an electrochemical galvanic fuel cell type oxygen sensor of the type that is extensively used to measure oxygen concentrations from 0% to 100% in gas streams.