Scope:

ASTM E1815 test method gives a relative means of classifying industrial radiography film systems. The film system consists of the film and the processing system that goes with it. Only direct exposure-type film exposed with lead enhancing screens should be tested using this procedure. This test method cannot accurately measure the performance of films exposed to fluorescent (light-emitting) intensifying screens.

Procedure:

In ASTM E1815, the measurement equipment is used for classification if this equipment and the corresponding test procedures produce the same results with an uncertainty of less than 5% and a confidence level of 95% for gradient G2, less than 7%, and a confidence level of 95% for gradient G4, and less than 10% and a confidence level of 95% for granularity. Compared to the test method of 7.1 to 7.4 for the film systems to be categorized, this shall conform with ISO/IEC 17025.

Specimen size

The microdensitometer’s inflow aperture must be roughly circular, with a diameter of not less than 1.2 times or more than 2 times the diameter of the efflux aperture.

Data
G = dD /d log₁₀ K

where:

K is the dose required for density D − Do, and Do is the fog and base density.

Conclusion:

ASTM E1815 test method gives a relative means of classifying industrial radiography film systems.