| 摘要 |
983, 669. Electric tests. BECKMAN INSTRUMENTS Inc. March 6, 1963 [April 4, 1962], No. 8907/63. Heading G1N. [Also in Division H2] To enable a polarographic cell for measuring gas concentration, in particular oxygen concentration, to be reactivated it is made in two parts 12, 14, the part 12 containing the electrodes and the electrolyte and the part 14 comprising a socket which carries connections to the measuring apparatus. As shown the part 12 comprises a cup 26 of epoxy resin which contains the gelled potassium chloride electrolyte, the silver anode 18, 20 and a coaxial gold cathode 16, 56. A P.T.F.E. diaphragm 36 is held in place by an epoxy resin cap 38 the body of the cup 26 being strengthened by a silver ring 50. The cap 38 has a central bore to allow gas to reach the diaphragm 36 which is separated from the cathode by a thin film of electrolyte. The socket portion 14 makes connection to the anode and cathode through female connectors 78 and 66 the latter having a screw thread to retain part 12. A thermistor 88 compensates for temperature variations. The metal of the female connectors is preferably harder than the anode and cathode as the latter may be discarded and replaced by another unit. A hole 34 allows for expansion or contraction of the electrolyte. The unit is stated to be particularly applicable to oxygen measurements in a pilot's face mask. Silver chloride formed by reaction of silver with the electrolyte stabilizes the depolarization current.
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