The ancient Egyptians drank flat beer because they had to. Could be they invented that beverage, but they never figured out how to put fizz into it. Today's beer-drinkers expect a decent head of foam on their brews and want what's underneath it to taste right too. The same goes for colas and other carbonated soft drinks. But too great a concentration of dissolved oxygen can produce off-flavors in any bubbly beverage and also flatten its froth.
Emerson Process Management is out to save your suds with the Rosemount Analytical Model Bx438 dissolved oxygen sensor, designed to monitor trace levels of dissolved O2 in beer and other beverages and to withstand more caustic clean-in-place cycles than competing devices. The sensor has a twist. Most dissolved O2 sensors operate by reduction of oxygen at the surface of the cathode. If the cathode is in direct contact with the liquid, contamination from proteins and other fouling agents in the process can cause inaccurate readings. The Rosemount cathode is covered with a gas-permeable membrane. The oxygen diffusing through the membrane is completely reduced at the cathode, and the current between anode and cathode is proportional to the oxygen content in the sample. The thick, steel-mesh-reinforced, double-layer membrane lets the sensor withstand elevated pressures and temperatures while maintaining high diffusion rates. Furthermore, the acidic electrolyte allows the sensors to outlive devices using alkaline electrolyte solutions. The results are stable outputs, fast response times, less maintenance—and better beer and soda.