In article <1996Jun15.094551.81778 at cc.usu.edu>, slktt at cc.usu.edu (O Monje) says:
>This will work.....and you can get over 1000 umol m-2 s-1. Now, you can choose the
>type of lamp depending on wether your plants require blue light or not. HPS lamps (high
>pressure sodium) lamps have no blue light, while MH (metal halide) lamps have plenty.
>Blue light is important for stem elongation......Fluorescents are cool (in terms of heat) but
>they age with time.....you might get 500 umol m-2 s-1 tops!
We used 6 Tungsten-halogen incandescent lamps (Osram, Halo Star KLR 51, 50W 12V)
and got over 1000 umol m-2 s-1. They have a diathermic reflector which reflects very few
infrared light. You will have 66% less heat radiation in the focussed beam (says Osram).
This lamp has nearly no blue light, but this doesnt matter for short time measurements.