Interesting question - what wavelengths specifically do you expect to detect? If I recall correctly the H20 attenuation of UV bands are low but the type of detector you'd need depends on what band you need to measure. Let me know and I might be able to recommend some of the meters I've used in the past. DRG
what is the range of wavelength to be measured?. You can build it by yourself. Silicon phtodiodes and phototransistors respond the UV radiation. There is also optical resistive sensors. You can add to the sensor an amplifier and a data logger.
We have produced two different deep Ocean spectrometers using a 224 nm laser and PMT array detectors for organic and microbial detection. These instruments were deployed to depths below 5 km.
THe two largest manufacturers for these interments are Biospherical Instruments and Satlantic - portable, however, is open to discussion - there are broad band sensors for UVA and UVB out there that are waterproof (International Light comes to mind) - but all of this depends on what wavelengths, how deep, how portable, and how much money you have to spend
Hi fellows. Thank you all for the suggestions. I fact we wish to detect (despite de attenuation) UVA and UVB bands in very shallow coastal waters and experimental design too.
You might want to consider UV dosimetry if you are working in shallow coastal waters if they are short term measurements. Search for work done by Peter Schouten and Nathan Downs have a look at what at what they have done on coral reefs and shallow still inland water bodies. I know Peter has used an instrument called IL1400 made by International Light Technologies and used an exceptionally long fibre optic cable to link sensor to the meter. The sensor was fine underwater (however it is a much older model though than that currently marketed so you would want to check on the currently available ones) but the connections need to be waterproofed. You could also find out if Ocean Optics make specific spectrometers that can be submersed. I have used their equipment but not for underwater purposes. Be sure that if you choose to make your own or modify an existing meter, that you ensure the waterproofing method will not absorb UV and potentially impact on your measurements. Good luck!
Dosimetry is a good option - David Kieber also published some protocols using UV actinometers, require no special equipment other than a spec - Jankowski et al., 2000. Photochem. Photobiol. 71: 431-440. The IL1400 is the International Light instrument I have with UW sensors - its OK for what it does and not too expensive
I'd also agree with Joanna - I used IL meters for phototherapy dosimetry and they were excellent for that purpose, but if you wanted them submerged you'd have to check out casing options. One other consideration is your filter / diffuser optics; I assume you're measuring solar UV in water? In that case wide filters are probably absolutely fine, but you may want to check out filter and diffuser options to be sure. They're discussed in some detail in this paper by Pye and Martin;
http://iopscience.iop.org/0031-9155/45/9/319/
and you'll find some more information on my publications page from my own work on subject if that helps. I purchased some relatively cheap hand held UVB meters a few years back that gave pretty good accuracy but I cannot remember for the life of me the company who sold them; I'll see if I can dig it out the company details.
In the old days - International light sold sensors for the IL1400 that were waterproof (you don't have to do them yourself and worry about optics etc) - check now to see if they are still available
The answers of the colleagues are okay. But i would propose for Arthur to undertake a search on the finished UV-A and UV-B sensors and surely he will be able to decide for the most suitable sensor from the point of view of the performance specifications and cost. however, i would encourage him to build one by himself.
He needs a filter and detector as well as a diffuser and signal conditioning circuit.
Concerning the sealing against water, he may not need to immerse the sensor but he may better receive and transmit the light by a suitable glass fibers and keep the sensor out side the water. There are silicon photodetectors that have good sensitivity to UV.
Thank you
The IL will not give you very valuable spectral data for UV. We have had really excellent experience with Biospherical Instruments Inc. (San Diego, California, USA) BIC radiometers. They are expensive, but very user-friendly, stable, rugged, and dependable. We have been using them for over 20 years and the first instruments we ever bought (then called a PUV) have traveled all over the world and are still working. If you need a less expensive instrument, you might look at the intercomparison that was published:
Kirk, J. T. O., B. R. Hargreaves, D. P. Morris, R. Coffin, B. David, D. Fredrickson, D. Karentz, D. Lean, M. Lesser, S. Madronich, J. H. Morrow, N. Nelson, and N. Scully. 1994. Measurement of UV-B radiation in two freshwater lakes: an instrument intercomparison. Archiv fur Hydrobiologie Beihefte Ergebnisse der Limnologie 43:71-99.
Although this is an old paper, it is still relevant to what is on the market today.
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