The computer code that provided the most complete information of how the process worked is titled “COMPSELECT”. From this reference, the RIT papers, and other patents, I was able to cobble together the parameters for controlling the Crystal Habit from CubicCubo-octahedralOctahedralTabular. The targets were given for the initial potassium bromide concentration, temperature, along with the minimum and maximum bromide concentration breakpoints for each crystal habit zone. The formulas for the Nernst and Debye Huckle equations were embedded as well. The code also contained two-point calibration checks for the silver billet electrode. From all of this I was able to extract enough information to gain an understanding for controlling the silver ion concentration during the precipitation by modulating the salt and silver jet flow rates under PID control and ramp segments. The evolution of this process from the art of making silver halide emulsions to the science of making them is interesting.

George