Kodak used syringe systems for some flows due to the limitations of pumps. The ratio of high to low flow rates required many pumps. This ratio is called the "turndown ratio". There was a very long series of threads on various methods for doing this and Bob Mazzullo contributed a lot of good ideas and drawings.

The air or gas driven system is good but does require a flow meter to get enough precision, as well as a regulator to add vAg control. Feedback is difficult.

As with most emulsions, you will need a minimum of about 5 delivery systems. AgA, AgB, XA, XB and XC. These represent 2 concentrations of silver and two of 2 different salts. To make my 1 L emulsion, I delivered 300 ml of silver and 300 ml of salts (approx) to a 300 ml starting kettle. So, consider that your delivery systems will need to contain up to 300 ml.

PE