ASNT Industrial Radiography Radiation Safety Practice Test

What is the specific gamma ray constant for Ir-192 expressed as?

1. 14 R/h at 1 ft

2. 5.3 R/h/Ci at 1 ft

3. 0.2 R/h/Ci

4. 66.7 R/h

The correct answer is: 5.3 R/h/Ci at 1 ft

The specific gamma ray constant for Iridium-192 (Ir-192) is expressed as 5.3 R/h/Ci at a distance of 1 foot. This value is crucial for radiation safety in industrial radiography, as it allows radiation safety professionals to calculate the exposure rate from a gamma source based on its activity (measured in curies, Ci) and the distance from the source. Understanding this constant helps radiographers determine appropriate safety measures and shielding requirements when working with Ir-192 sources. The specific gamma ray constant takes into account both the nature of the radiation emitted by the isotope and the standard distance from which measurements are typically taken. Utilizing this value ensures that personnel can be adequately protected from radiation exposure, adhering to established safety protocols.