PID Lamp (Photoionisation Detector Lamp)
The PID technique uses a lamp with known photon energies in the vacuum ultraviolet (VUV) region.
The output from the lamp is used to photoionise gaseous molecules with ionisation potentials lower than the photon energy emitted. Typical photoionisation detectors measure volatile organic compounds (VOCs) and other gases in concentrations from the ppm to ppb level.
