The G1010 oxygen gas analyzer and detector uses a galvanic oxygen cell to measure oxygen over an exceptional dynamic range of 100% to 0.1ppm (parts per million) in a variety of gases. The instruments are microprocessor- controlled and provide exceptional performance and versatility. A large multi-digit, auto-ranging LCD shows the concentration and user-adjustable parameters. Two alarm channels, user-programmable to be high, low or off, each provide one set of volt-free changeover contacts, and can be set to any concentration within the span of the instrument.