Abstract: A continuous analyzer for accurately measuring the free chlorine residual in a chlorinated water supply having an ammonia content which gives rise to a combined chlorine residual whose bactericidal effectiveness is poor as compared to free chlorine. The analyzer includes an amperometric cell through which a sample from the supply is conducted, the cell being provided with a measuring electrode and a counter electrode. Connected in series with the electrodes is an external voltage source whose level is set to impress a potential on the measuring electrode at which the current flow in the cell as a result of the chlorine content of the sample increases progressively in accordance with the concentration of free chlorine residual, the cell being essentially insensitive to combined chlorine residual.

Abstract: A technique for continuously indicating the concentration of ozone dissolved in water, use being made of an amperometric cell, preferably formed of a gold cathode concentrically disposed within a tubular copper anode to define an annular passage, the cathode being rotated at high speed. A sample stream of the water is directed through the passage at a predetermined flow rate whereby in the absence of dissolved ozone, the cathode is polarized, but in the presence thereof, depolarization takes place to cause a current to flow in the cell, the current being measured to provide a reliable and continuous reading of ozone concentration.

Abstract: A residual chlorine analyzer for testing chlorinated water, and including an amperometric cell whose flow passage is provided with spaced measuring and counter-electrodes both formed of copper. A sample stream diverted from the water to be tested is continuously conducted through the flow passage between the electrodes. Impressed across the electrodes is a voltage which renders the measuring electrode negative relative to the counter-electrode to an extent causing the cell to operate in a saturation voltage zone wherein the intensity of current passing through the cell is independent of changes in the impressed voltage and is proportional to the bulk concentration of the chlorine in solution. The current is measured by a meter calibrated in terms of concentration to maintain an uninterrupted, in-line check on residual chlorine in the water.