GB781139A - Improvements in or relating to exposure meters for x-ray photography - Google Patents

Abstract

781,139. X-ray apparatus. MASSIOT & CIE. SOC. ANON., G. Oct. 31, 1955 [Nov. 8, 1954], No. 31102/55. Class 98(1) Means for measuring radiation dosage over a wide range of wave-lengths includes at least two photographic emulsions with different sensitivity characteristics over the range, in juxtaposition with filtering means of different characteristics. In Fig. 2, photographic films 1 and 2 are placed in juxtaposition with a copper sheet 6 and tantalum sheets 7, 8 and 9. In Fig. 10, a photographic film 21 is backed by a lead sheet 22 of 2 mm. thickness, a copper sheet 23 of 2.07 mm. thickness, and a tantalum sheet 24 of 0.1 mm. thickness. A second photographic film 25, which is three times as sensitive as film 21, is placed behind these sheets, and is backed by a lead wall 26. In Fig. 12, a photographic film 31 is backed by a lead sheet 32 of 0.2 mm. thicK- ness, a tin sheet 33 of 0.7 mm. thickness, and a lead sheet 34 of 0.2 mm. thickness. Behind these sheets is placed a second photographic film 35, ten time as sensitive as film 31, with a lead backing 36. The films and other Layers may be packed in a light sealed pocket carried on the person in a plastic packing. Alternatively, they may be placed in a lead lined box, which box is in turn carried in a casing 13, Fig. 7. A spring clasp 15 inserted in opposite slots 14 in the casing 13 serves to retain the lead lined box in the casing, and to act as a means of suspension.