T.O. 33B-1-16-71Figure 6-35. Sketch of Desirable Stepped Block for Radiation Measurements.6.7.4.3 PlottingtheData.NOTEThe Constant Exposure Chart is for a single kilovoltage setting. Additional curvesfor other kilovoltages can be made by repeating the procedure at any desiredkilovoltage.Make density measurements of each step of the radiographs with a densitometer and record this data in a table. Thefinal table should show a density for each step thickness at each exposure. Now plot this data on semilogrithmic graphpaper with density and object thickness as the coordinates. This will give a set of curves, one for each exposure. Thisis a Constant-exposure chart and is only one type of technique chart.6.7.4.4 ConstantDensityCharts.It is more common to plot technique charts in the form shown in Figure 6-36. This is a constant-density chart for threedifferent kilovoltages. To prepare this type of technique chart, it is necessary only to plot points taken from the graphprepared in Paragraph 6.7.4.3. Record and plot the points for each thickness at the intersection of the selected densityand exposure curves. This will result in a single curve on the constant density chart for one kilovoltage.
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business
