Abstract: A colorimeter for continuously monitoring the concentration of an ionic species in an aqueous solution comprises a source 30 of optical radiation, a flow cell 10 including three flow chambers 11, 12 and 13 interconnected so that a sample of the solution can pass through each flow chamber in succession, and photodetector devices 41, 42 and 43 positioned to respond to radiation transmitted through the solution in the flow chambers 11, 12 and 13, respectively. The lengths of the three flow cells are different from each other to provide a continuous real-time calibration check based upon photodetector responses to radiation transmitted through different quantities of the solution. Electronic circuitry interconnecting the radiation source 30 and the photodetector devices 41, 42 and 43 maintains the intensity of the radiation emitted by the source 30 at a substantially constant value.

Abstract: In a reactive metal-water electrochemical cell, an anode-cathode configuration providing for direct anode-cathode contact by use of a mesh-screen cathode essentially contacting the anode over its full surface. Optionally, the screen is supported on a plurality of ribs formed on or attached to a cathode backplate, the ribs forming electrolyte channels between the cathode screen and the cathode backplate.The configuration can be utilized for both unipolar and bipolar electrodes. Provision is made for maintaining contact between the cathode screen and the anode as the anode is consumed, thereby maintaining efficiency of the battery. Voltage and power output of the cell is controlled by varying electrolyte concentration or temperature, or both.

Abstract: In a reactive metal-water electrochemical battery, means for minimizing the destructive erosion of the reactive metal anode material on those anode surfaces not being actively employed in the operation of the battery. More particularly, in one embodiment, the non-working anode surfaces are maintained in intimate relationship with the battery casing to prevent the eroding electrolyte from contacting the non-working surfaces. In another embodiment, the electrolyte is confined to the working surface of the anode by means of flexible seals which protect the non-working surfaces.

Abstract: In a reactive metal-water electrochemical cell, a configuration utilizing waste heat and evolved hydrogen gas for pumping electrolyte through the cell. More particularly, the cell is in a vertical, hollow tubular configuration with the reactive anode being bonded to the interior surface of the tube casing and a coiled metal screen cathode being positioned within the tubular cell and containing the anode over essentially its full working surface. As the anode is consumed in operation, by reaction with an aqueous electrolyte filling the interior cavity of the tubular configuration, the coil configuration of the cathode forces it to expand and maintain contact with the anode. During operation, evolved waste heat and gas cause a flow of electrolyte through the interior of the cell.