The Gasurveyor 500 series are the most flexible instruments on the market today. Available in 2 and 4 button models, built-in sampling pump, large LCD with automatic backlighting, audio, visual and fault alarms, data logging and a wide variety of probes makes this series perfect for any of your gas detection needs. The instruments are configurable to suit any department, including Construction, Leak Survey and Customer Service, by simple selection of hardware and software. The 500 series measures flammable gases and vapors. Available ranges include PPM, LEL and Volume Gas, Oxygen, CO, and H2S.