The AccuPAR model LP-80 is a menu-driven, battery-operated linear PAR ceptometer, used to measure light interception in plant canopies, and to calculate Leaf Area Index (LAI). It consists of an integrated microprocessor-driven data logger and probe. The probe contains 80 independent sensors, spaced 1 cm apart. The photosensors measure PAR (Photosynthetically Active Radiation) in the 400 to 700 nm waveband. The AccuPAR displays PAR in units of micromols per meter squared per second (µmol m−2s−1). The instrument is capable of hand-held or unattended measurement.