Value of total filtration for 70 kVp is
Total filtration is the sum of the inherent and added filtration. Governmental regulations require the total filtration in the path of a dental x-ray beam to be equal to the equivalent of 1.5 mm of aluminum for a machine operating at up to 70 kVp and 2.5 mm of aluminum for machines operating at higher voltages.
Oral Radiology, Principles and Interpretation / Stuart C. White, Michael J. Pharoah - 7th ed - pg - 10,11
2.1 mm
2.3 mm
1.5 mm
2.5 mm