Automatic chemical analyzer and controller

Claim 3

an adjusting drain operatively associated with each said etchant solution containing means, said drain normally closed;

Claim 5

means for selectively sampling the etchant solution in each said etchant containing means comprising a solenoid actuated sampling valve operatively connected to said etchant containing means and responsive to said stepping relay;

Claim 6

a caustic reservoir selectiVely controlled by an addition valve which is in operative relationship to said etch solution containing means;

Claim 7

a water source in operative relationship to said etchant solution containing means, and said constant level control; B. a control section comprising

Claim 8

means for containing a standard acid solution;

Claim 9

metering means operatively associated with the said acid-containing means and said etchant solution sampling means operative to neutralize the etchant sample wherein said metering means comprises first and second dual-proportioning pumps, said first pump operative to continuously meter standard acid solution from said standard acid solution container to neutralize a first given portion of the sample etch solution for determination of a first equivalence point indicating caustic content, said second dual-proportioning pump operative to continuously meter sufficient standard acid solution from said acid solution container to neutralize a second given portion of the caustic and inhibitor of the sample etch solution for determination of a second equivalence point indicating inhibitor content;

Claim 10

means for mixing the sample etchant solution and standard acid solution comprising a mixing chamber for each said dual-proportioning pump operative to mix the etchant sample, standard acid solution and water;

Claim 11

first and second timing means operatively associated with said addition valve and said adjusting drain responsive to a pH detecting means to determine the duration of the caustic addition and control flow therefrom;

Claim 12

means operative to detect the equivalence point pH values of the caustic and inhibitor resultant from the mixing of the etch solution sample and standard acid solution, said means causing the addition of caustic if the first equivalence pH value indicates a caustic deficiency and opening said adjusting drain if the second equivalence pH value indicates an excess of inhibitor, said detecting means comprising a flow chamber in communication with each said mixing chamber, a pH meter operatively associated with each said flow chamber, a first of said pH meters measuring the pH of the sample solution from said first mixing chamber to determine a first equivalence point of the sample solution, a solenoid responsive to said first pH meter wherein, if the sample solution has less than a preset pH value indicating depletion of caustic, said first pH meter actuates said solenoid, actuating said first timer means to open said addition valve in said tank section, a second of said pH meters measuring the pH of the sample solution from said second mixing chamber to determine a second equivalence point of the sample solution indicating inhibitor buildup, a solenoid responsive to said second pH meter and operative to actuate said second timer means, said second timer means opening said tank section, adjusting drain for a preset period to reduce inhibitor buildup.