A Description of the Philips SO2 Monitor

Strict standards for ambient sulfur dioxide requirements in the San Francisco Bay Area result in strict criteria for monitor operations by private industry. Of nine different monitors tested, three are acceptable. One, the Phillips PW 9700, senses sulfur dioxide by coulometric reaction with bromine in a potassium bromide solution. The monitor has a high degree of sensitivity, rapid response, and stable attendance or maintenance is aided by quality construction, internal reagent supply, and elimination of reagent pump. Options include automatic zeroing and calibration, probe filter and heater, and telemetering output.