Development Of External Beam Therapy 3 Ultraviolet Dosimeter
Loading...
Date
2018-06
Authors
Ahmad Shah, Wan Insaniah Saleha
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Solar ultraviolet radiation is well known to potentially brings harmful effect to human health when exposed in a prolong nature. Hence, the routine measurement of exposed solar ultraviolet (UV) dose is essential. The existing method in determining solar UV exposure is through UV meter. The problem found in this method is that it can only allow a single point measurement (i.e, an instantaneous UV intensity) in mW/cm². This means it does not record accumulative UV dose at one time. So, for this instrument to operate, it requires continuous exposure to outdoor environment which may cause defect to the instrument due to overheating. Besides time consuming, the replacement for the defective device also added to the cost. Thus, this research proposed the use of Gafchromic EBT 3 film as it can record accumulative UV dose, disposable, mobile and have good correlation with UV. Besides that, an instrument is needed to interpret the accumulation of dose (i.e, color changes) from EBT 3 film after exposure. But, the commonly used instruments to interpret the color changes of the films are still relying on conventional methods (i.e. scanner and spectrometer) where these devices are bulky, expensive and the end user needs a software application to further analyze the color information from the film. Therefore, this research has developed a 10-bit microcontroller based EBT 3 UV dosimeter (in mJ/cm²) that comprised of a single light-emitting diode (LED) with a peak emission wavelength at 634.89 nm as the illumination light source and a transimpedance photodiode as the sensor. This dosimeter can instantly determine and display solar UV-A and B dose in mJ/cm². Prior to the development of the system, a quantitative analysis through the application of visible spectroscopy system and LEDs - photodiode based optical measurement has been conducted on a set of 50 EBT 3 samples with incremental solar UV (exposure) doses.
Description
Keywords
Solar ultraviolet radiation is well known , brings harmful effect to human health