This app calculates the Geometric Unsharpness Ug for industrial radiography. It will then calculate the Geometric Unsharpness Ug for you. No more have to look up the formula and pulling out a calculator.
D300mm Distace from Source Side of Weld to Radiographed to the Film.
Geometric unsharpness or the size of the penumbra Ug shown in the image above can be calculated using the following equation. SID OID and FSS. For the case such as that shown to the right where a sample of significant thickness is placed adjacent to the detector the following formula is used to calculate the maximum amount of unsharpness due to specimen thickness. If the distance is doubled the intensity is 4 times less what should you do to the mAs to keep the same receptor exposure.