UV monitors

Peter Lundskow <plundskow [at] dnr__state__in__us> writes

>Recently, we purchased a more accurate meter, the UVX Radiometer
>from UVP Ultra-Violet Products (this meter comes with certification
>of calibration)it takes readings in microwatts per cm squared.  I
>have not been able to find any information on how to convert one
>measurement to the other and what safe readings would be for museums
>when measured in microwatts per cm squared. ...

The formula for calculating proportional UV in microwatts/lumen,
given visible light in footcandles and UV in microwatts/square cm
is:

    UV/visible light*929

2 microwatts/square cm at a visible light level of 25 fc is roughly
equivalent to 75 microwatts/lumen. 0.4 microwatts/square cm at a
visible light level of 5 fc is roughly equivalent to 75
microwatts/lumen

It's important to remember that published proportional UV standards
ASSUME that a given visible light level is being maintained.  If you
have not first established a visible light standard, establishing
standards of proportional UV are largely meaningless.

Will Jeffers
Collections Care Scientific Research Assistant
Scientific Research Laboratory
Museum of Fine Arts
465 Huntington Avenue
Boston MA 02115-5597
617-369-3466
Fax: 617-369-3702


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                  Conservation DistList Instance 17:17
                  Distributed: Thursday, July 31, 2003
                       Message Id: cdl-17-17-004
                                  ***