INSTRUMENTS BASED ON POLAROGRAPHIC SENSORS FOR THE DETECTION, RECORDING AND WARNING OF ATMOSPHERIC OXYGEN DEFICIENCY AND THE PRESENCE OF POLLUTANTS SUCH AS CARBON MONOXIDE *
Atmospheres containing insufficient oxygen to support life are sometimes formed in mines and in many other industrial environments, usually in the form of layers or pockets of gas. These atmospheres can be detected, and their boundaries defined with oxygen-measuring instruments that have been developed to an advanced stage; indeed, commercial versions of some of the instruments, produced under a licence from the National Research Development Corporation, should soon be available. The instruments are based on an improved form of polarographic electrode which consists of a metallized membrane, and they include a pocket-size meter, a miniature audible alarm, a flashing cap-lamp alarm, and a recorder with a remote sensor and a flashing alarm. A similar system has been investigated as a means of measurement for dangerous concentrations of carbon monoxide, and a pocket-size meter has been constructed. An adapted form of the metallized membrane electrode has also been used for measuring dissolved oxygen.