FPA 4100 monitors specific compounds in both gas and liquid samples using either UV or visible light sources and boasts temperature controlled photo diode block for maximum signal stability. The FPA 4100 controller includes an intuitive user interface with an intrinsically safe, removable keypad, LCD screen, 10 LED indicator lights, and data-loading capability. Rugged and reliable, the systems offer multi-stream-analysis capability, delivering precise continuous measurement with no reagents or compressed gases required.