. Elementary and dental radiography . known, reference can be madeto a printed table and the exact time of exposure necessary commending such work as efforts along the right line, I considerthem failures so far as practical application in dental work is that in the calculate n the density of the pari and sensitiveness ofthe plate are not taken into account at all. IXC RADIOGRAPHS 7$ Each man must learn to properly time his exposure by personal ex-perimentation. This statement is likely to be contradicted by those whoconstrue it to mean that no idea at all of
. Elementary and dental radiography . known, reference can be madeto a printed table and the exact time of exposure necessary commending such work as efforts along the right line, I considerthem failures so far as practical application in dental work is that in the calculate n the density of the pari and sensitiveness ofthe plate are not taken into account at all. IXC RADIOGRAPHS 7$ Each man must learn to properly time his exposure by personal ex-perimentation. This statement is likely to be contradicted by those whoconstrue it to mean that no idea at all of the time of the exposure can belearned except by experiment. That is not what I am saying, idea 1 wish to convey is that these tables of calculation, on the timeof exposure, give only the approximate length of time of exposure neces-sary, and that a very little experience and the use of judgment renderthem useless. They are always useless except when a penetrometer isused and the coil is equipped with a 2. Trays for developing and fixing solutions. To make the negative (the picture on the glass of the plate) of theradiograph shown in Fig. 71, the factors were as follows: 1. Machines used—an 18-inch induction coil, with a two-point elec-trolytic interrupter, operating on no-volt, D. C. circuit. All resistanceof rheostat cut out. 2. Strength of current. Machine not equipped with amperemeteror milliamperemeter. Approximate amperage of the primary current,26. Secondary current sufficiently powerful to obtain a fat. fuzzy spark10 inches long. 3. Penetration of X-rays. Tube backs »up 7 inches of parallelspark. Distances of tube regulating spark gap 4 inches. Therefore, thetube is high and the rays from it quite penetrating when it is properlylighted. 4. Distance of target from plate. Seventeen (17) inches. 5. Thickness of part. That of the hand, about 1^2 inches at thick-est part. 6. Density of part. That of hand. 7. Plate used. Lumiere special X-ra
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisheretcet, bookyear1913
