Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC) (original) (raw)
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Journal of Photochemistry and Photobiology B: Biology, 2013
The spectral response of solvent-cast polyvinyl chloride (PVC) thin film suitable for use as a long-term UV dosimeter has been determined by measuring the UV induced change in the 1064 cm À1 peak intensity of the PVC's infrared (IR) spectra as a function of the wavelength of the incident radiation. Measurements using cutoff filters, narrow band-pass filters and monochromatic radiation showed that the 16 lm PVC film responds mainly to the UVB band. The maximum response was at 290 nm and decreasing exponentially with wavelength up to about 340 nm independent of temperature and exposure dose. The most suitable concentration (W/V%) of PVC/Tetrahydrofuran solution was found to be 10% and the best thickness for the dosimeter was determined as 16 lm.
Development and characterisation of an ultra-long exposure UV dosimeter
2014
Excessive exposure to solar ultraviolet (UV) radiation is known to have detrimental effects on human health, some of which are cumulative in nature with impacts that may arise after years and decades of exposure. Therefore, it is important that the risk associated with prolonged UV exposure can be investigated; this requires long-term studies in which large-dose measurements can be accurately quantified. Chemically-based UV dosimeters have been widely used to measure personal UV exposure since 1976. Despite the development of electronic UV dosimeters, chemical dosimeters maintain their suitability in human exposure research as versatile, labour- and cost-effective UV monitors that require no power. The main limitation of existing chemical dosimeters is their short dynamic measurement range, as they are saturated after relatively short exposure times. Consequently, prolonged personal UV exposures are estimated either from measurements spanning just a few days, with high uncertainty, ...
Physics in Medicine and Biology, 2003
The optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) film have been characterised in order to develop an alternative method for UV dosimetry with a focus on long-term human exposure measurements. The dynamic range of PPO film was found to extend to 2 MJm -2 of broadband UV exposure independently of film thickness, providing an exposure range of roughly four summer days at subtropical latitudes. The sensitivity of the film to UV exposure was positively related to film thickness in the 20 to 40 μm range. Films of 40 μm thickness proved to be the most suitable for long-term human UV exposure measurements.
Agricultural and Forest Meteorology
Research on the influence of ultraviolet radiation (UV) on terrestrial plants and on its link with other influencing environmental factors requires information on UV exposures, both for a horizontal plane and specific portions of a plant, above and under the canopy. In this research, one set of UV dosimeters based on unstabilized polyvinyl chloride (PVC) were employed to measure the unweighted UVB (UVB) and the biologically effective UV radiation for plant damage (UVBEplant) incident on the leaves of a plant for a month, without having to change the dosimeters. The exposures were compared to the cumulative exposure concurrently measured with six sets of unstabilized polyphenylene oxide (PPO) dosimeters that required changing every four to six days. The difference in exposures between the two types of dosimeters was on average within 11%. The PVC dosimeter is the first reported polymer film dosimeter with a useable range of a month for measuring the plant damaging UV and the UVB exposures to specific parts of a plant. The exposure period of a month for the PVC dosimeter is an extension by a factor of four over the useable range of dosimeters previously reported in the literature for evaluation of the exposure of plants to UV radiation.
AN EVALUATION OF NALIDIXIC ACID FILM AS A UV-A RADIATION DOSIMETER
Photochemistry and Photobiology, 1983
Nalidixic Acid (NA)' incorporated into a polyvinyl chloride film has recently been proposed as a UV-A radiation dosimeter. A trial. in which two different batches of NA film were exposed to both solar simulating and monochromatic 330 nm radiation is described. With both batches o f film a linear relationship was observed between the UV-A fluence derived from the NA film and the Huence determined with conventional electronic radiometric equipment. There was, however. considerablc hatch variation in response to UV-A radiation. Corrections may be made for batch differences. If the batch response can be standardized. our results would support the use of NA film as a simple routine method of measuring UV-A radiation
The optical properties of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) film have been characterised in order to develop an alternative method for UV dosimetry with a focus on long-term human exposure measurements. The dynamic range of PPO film was found to extend to 2 MJm -2 of broadband UV exposure independently of film thickness, providing an exposure range of roughly four summer days at subtropical latitudes. The sensitivity of the film to UV exposure was positively related to film thickness in the 20 to 40 μm range. Films of 40 μm thickness proved to be the most suitable for long-term human UV exposure measurements.
SUNTEST: a chemical UVB radiation dosimeter
Journal of Photochemistry and Photobiology B: Biology, 1995
A simple disposable chemical UVB radiation dosimeter with silver-mercury--oxalate suspension, SUNTEST, was developed for use by the general public. Its spectral sensitivity curve closely matches the erythemal action spectrum. SUNTEST takes account of the variables influencing the length of sunbathing. The dose of solar UV radiation can be evaluated from the darkening of the dosimeter, from white to dark brown. On the basis of the results of a 5 rain exposure, recommendations are given for safe exposure times (which do not produce sunburn) for different skin types. Regular use of this simple UVB dosimeter will contribute to the prevention of acute adverse effects of solar exposure; like any limitation of UV exposures, it may be expected to reduce also the late adverse effects, including skin malignancies.
Biological and physical dosimeters for monitoring solar UV-B light
Journal of Radiation Research, 1990
A biological dosimetry system for measuring solar UV-B light was established using bacteriophage T1 with E. coli Bs-1 as the host cell. Also a new physical UV-B dosimeter was developed which can specifically detect the UV spectral region related to inactivation of phage T1. Phage T1 is very stable in liquid suspension and it has adequate sensitivity to measure the intensity of solar UV-B. In addition, the survival of phage T1 responded linearly to UV fluences when plotted semi-logarithmic ally. Thus T1 seemed to have characteristic features making it suitable material as a biological dosimeter for sunlight. Outdoor experiments throughout one year showed that the mean amount of solar UV light in summer was about 6 fold larger than that in winter at Isehara (139.5 degrees E, 35.5 degrees N), Japan. A novel physical dosimeter which responds faithfully to UV-B light under atmospheric conditions on the ground was developed as well. The spectral response was very close to that of biological materials. Readings of this UV-B dosimeter could be converted into the efficiency of sunlight upon biological materials. This instrument is compact; it can also be used as an erythemal dosimeter.
A Critical Assessment of Two Types of Personal UV Dosimeters
Photochemistry and Photobiology, 2011
Doses of erythemally weighted irradiances derived from polysulphone (PS) and electronic ultraviolet (EUV) dosimeters have been compared with measurements obtained using a reference spectroradiometer. PS dosimeters showed mean absolute deviations of 26% with a maximum deviation of 44%, the calibrated EUV dosimeters showed mean absolute deviations of 15% (maximum 33%) around noon during several test days in the northern hemisphere autumn. In the case of EUV dosimeters, measurements with various cutoff filters showed that part of the deviation from the CIE erythema action spectrum was due to a small, but significant sensitivity to visible radiation that varies between devices and which may be avoided by careful preselection. Usually the method of calibrating UV sensors by direct comparison to a reference instrument leads to reliable results. However, in some circumstances the quality of measurements made with simple sensors may be overestimated. In the extreme case, a simple pyranometer can be used as a UV instrument, providing acceptable results for cloudless skies, but very poor results under cloudy conditions. It is concluded that while UV dosimeters are useful for their design purpose, namely to estimate personal UV exposures, they should not be regarded as an inexpensive replacement for meteorological grade instruments.