The 2280A is a system for continuously monitoring H2S gas concentrations in four locations. The system consists of up to four remote mounted sensors and a solid state controller. The controller consists of four independent channels, each having its own circuitry. With a digital display, the 2280A shows hydrogen sulfide gas concentrations in ppm (parts per million) in the ranges of 0-20, 0-50, or 0-99 ppm for each channel.