M. Rougier et al., A DEVICE FOR STUDYING THE EFFECTS OF RADI ATION ON THE PERSISTENCE OFPATHOGENIC MICROORGANISMS, Agronomie, 14(10), 1994, pp. 673-681
A system was devised for separate analysis of the photic effect and th
e thermal effect of solar radiation on the persistence of pathogenic m
icroorganisms under both artificial and natural light. The objective o
f the authors was also to investigate these effects in varying waveban
d and irradiance. The irradiation chambers consisted of controlled-env
ironment incubators with 2 high-pressure metallic halogen lamps (400 W
) irradiating a large temperature-controlled platform (3 600 cm(2)). T
he light quality was modified by using 2 long pass glass filters. In u
sing a 295 nm cutting filter, the UVB irradiance ranged from 1.6 to 0.
4 W.m(-2) according to the distance from the source to the target plan
e. At 1.50 m distance the gradient of distribution of UVB irradiance o
n the target surface was less than 12%. The thermal gradient did not e
xceed 5%. The difference between the target temperature and the measur
ed temperature at the sample surface support was less than 1 degrees C
. The relative humidify remained stable around 60% during the inoculum
exposure. The device has been adapted for studies in 'semi-field' con
ditions (constant temperature for the support of inoculum and solar ra
diation).