. . . . . "SDN:S04::S0480" . "" . "PML/Chelsea Instruments 2-pi PAR upwelling light meter"@en . "accepted"@en . "A specific type of instrument with a hemispherical collector that measures electromagnetic visible radiation (400-700 nm) travelling in all directions over 180 degrees. Instrument mounted facing downwards to measure light travelling upwards."@en . . . . . .