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SPECTRAL QUALITY OF TWO FLUORESCENT UV SOURCES DURING LONG‐TERM USE
Author(s) -
Adamse Paulien,
Britz Steven J.
Publication year - 1992
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1992.tb02215.x
Subject(s) - fluorescence , ultraviolet , absorbance , irradiance , uv filter , irradiation , materials science , fluorescent lamp , chemistry , optics , optoelectronics , chromatography , physics , nuclear physics
— The characteristics of a fluorescent ultraviolet (UV) lamp (UVB‐313), UV‐B transmitting cellulose diacetate (CA) and UV‐B absorbing polyester (PE) films were determined during actual use. Although lamp emission was stable between 70 and 386 h of burn time (longer times were not investigated), the absorbance of UV‐B and UV‐A radiation by CA and PE films, respectively, increased with time when wrapped around lamps. As a result, the irradiance of lamp/filter combinations decreased steadily (even when CA films were presolarized for 10 h), making it necessary to compensate by adjusting the height of the lamp bank or by changing filters frequently. Note that corrective action is required for UV‐A controls (PE films) as well as UV‐B experimental treatments (CA films). Changing filters is preferable, since aging of CA filters caused shifts in the ratio of UV‐B to UV‐A. However, in spite of these shifts, the normalized spectrum of weighted biologically effective UV‐B radiation did not change to a large extent.