Hi all, about 2 weeks ago I posted several questions about JAZ OCean Optics spectrophotometer. I was wondering which light source (deuterium-tungsten or xenon pulsed) would be the most appropriate. First of all - I'd like to thank everyone who answered my concerns - you're comments were very useful and valuable :) From what I've received it seems clear that both light sources have pros and cons. Deuterium one: requires up to 30 min warm-up (which may be annoying) and generates significant amounts of heat, however offers very stable and smooth emission spectrum; xenon one is operational without warm-up and seems to require less power (which would be precious in field applications) but generates constant (although not very loud) noise and has more irregular emission spectrum. For me it's clear that PX-2 (xenon source) is better. As one of You mentioned, with PX-2 one has to be careful as the light seems to contain different amounts of shorter wavelengths right after turning on and later after several minutes so it's a good idea to take several measurements and average the spectra. Importantly I was reassured that JAZ with either PX-2 or DT does not require any additional powering module apart from the one powering the spectrophotometer. Thanks for all your remarks! Cheers, szymek -- Szymon Drobniak || Population Ecology Group Institute of Environmental Sciences, Jagiellonian University ul. Gronostajowa 7, 30-387 Kraków, POLAND tel.: +48 12 664 52 19 fax: +48 12 664 69 12 szymek.drobniak@uj.edu.pl www.eko.uj.edu.pl/drobniak geralttee@gmail.com