Development of Half Value Layer Measurement Device for Single X-ray Exposure

Full text: A portable single X-ray exposure HVL measuring device was developed. A photodiode detector coated with scintillator was selected for X-ray intensity measurements. The measuring system was connected to a microcomputer for data storage and analysis. The HVL was calculated from a single exposure by using an attenuated intensity from an aluminum wedge with continuous thickness of 0.5 to 5.0 mm. Then the measured HVL was calibrated with the corrected HVL measured by the standard device of the Department of Medical Sciences. The tested HVL measurements from the developed and the standard devices were performed with 6 X-ray generators used in various institutes in the high voltage supply X-ray tube range from 60 to 90 kV at distance between focal spot of X-ray tube to detector of 50 cm and HVL between 2 to 3 mm Al. The differences were found to be within -0.14 to +0.80 for exposure not greater than 50 mAs