RAE Systems is an innovator and the recognized industry leader in the development of photoionization detectors (PIDs). PIDs use ultraviolet (UV) rays to bombard gas samples and detect a broad range of VOCs such as formaldehyde, methane, and benzene, as well as hydrocarbons that typically occur in oil drilling and refining. These sensors provide an instant reading indicating whether gas is present. This makes PID sensors useful in go/no-go situations where personnel are unsure of what threats they face. RAE Systems offers PIDs that measure in parts-per-million (ppm), as well as specialized PIDs that are highly sensitive to low concentrations of VOCs, and can identify parts-per-billion (ppb). With fast and simple calibration and a large library of correction factors available for a variety of gases, our PIDs set the industry standard for reliability and accuracy.