Document Detail


Dosimetry of room-air germicidal (254 nm) radiation using spherical actinometry.
MedLine Citation:
PMID:  10483359     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
A method is demonstrated for measuring germicidal (254 nm) ultraviolet radiation (GUVR) in an omnidirectional manner. This method has application for those situations in which GUVR from more than one direction or source impinges on a three-dimensional object, and when it is of interest to determine the radiant fluence experienced by the object. For this purpose spherical quartz vessels were constructed varying from 0.8 to 1.25 cm in outside diameter. The vessels were filled with an actinometric solution consisting of KI and KIO3. This solution is optically opaque at 254 nm and is insensitive to room light. Upon exposure to GUVR this solution, which counts all of the 254 nm photons, forms triiodide. Following radiation, the contents of the vessel are removed, the absorbance of triiodide measured and the fluence rate determined based on a relationship that takes the volume to cross-sectional area of the actinometer into account. It is demonstrated that, in accordance with theory, the area of the sphere that intercepts the radiant energy is equal to the cross-sectional area of the sphere. A demonstration of the utility of this method was carried out in a test facility 90 m3 equipped with five GUVR lamps, one in each corner and one in the center of the room, arranged so as to irradiate the air in the upper portion of the room. Twenty spherical actinometers were evenly distributed around the room and exposed for either 30 or 90 min. The fluence rate varied from one part of the room to another, peaking near the GUVR lamps at 65-85 microW per cm2. By averaging over all 20 points, a pseudoaverage fluence rate for the room was found to be 42 and 44 microW per cm2 for the 30 and 90 min exposures, respectively. The similarities in the values for this metric demonstrates that the actinometric response is linear over this exposure range.
Authors:
R O Rahn; P Xu; S L Miller
Related Documents :
9002859 - Effect of corrosion on the strength of soldered titanium and ti-6al-4v alloy.
12379309 - Cholesterol crystallite nucleation in supersaturated model biles from a thermodynamic s...
17133829 - Inactivation of protozoan parasites in food, water, and environmental systems.
7996259 - Effect of three different preservative systems on the stability of extruded dog food su...
11537189 - The future of irradiation applications on earth and in space.
15880899 - On statistical relationship of solar, geomagnetic and human activities.
11368569 - Determination of n-(carboxymethyl)fumonisin b(1) in corn products by liquid chromatogra...
15596979 - Dietary deficiencies and excesses: a sample of african american mothers and daughters e...
24238799 - Anaerobic digestion of autoclaved and untreated food waste.
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Photochemistry and photobiology     Volume:  70     ISSN:  0031-8655     ISO Abbreviation:  Photochem. Photobiol.     Publication Date:  1999 Sep 
Date Detail:
Created Date:  1999-10-07     Completed Date:  1999-10-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0376425     Medline TA:  Photochem Photobiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  314-8     Citation Subset:  IM    
Affiliation:
Department of Environmental Health Science, University of Alabama, Birmingham 35294-0022, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Disinfection / methods*
Iodates / chemistry
Photochemistry
Potassium Compounds / chemistry
Potassium Iodide / chemistry
Radiometry / methods*
Ultraviolet Rays*
Chemical
Reg. No./Substance:
0/Iodates; 0/Potassium Compounds; 7681-11-0/Potassium Iodide; 7758-05-6/potassium iodate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Quantitative characterization and study of the relationship between constitutive-facultative skin co...
Next Document:  Effect of N-acetylcysteine on UVB-induced apoptosis and DNA repair in human and mouse keratinocytes.