Abstract: The present invention relates to of a coating composition containing a moisture-hardening binder based on organic polyisocyanates which is prepared by forming a mixture containing at least those auxiliaries and additives which are not completely dry and an isocyanate component a) which has an average NCO functionality of 1.05 to 1.8 and is based on the reaction product ofa1) a polyisocyanate mixture of the diphenylmethane series witha2) a monohydric C.sub.1-26 alkanol which may contain ether bridges,and after the isocyanate/water reaction is substantially complete, further mixing the mixture with an isocyanate component b) which has an isocyanate content of 2.5 to 25% by weight and any remaining auxiliaries and additives, the quantities of components a) and b) corresponding to a weight ratio of a) to b) of 1:1 to 1:30.The present invention also relates to a process for the preparation of these coating compositions.

Abstract: Control system and apparatus for measuring and monitoring the nitrogen oxides content of internal combustion engine exhaust gases. The exhaust gases are contacted with the reducing electrode of a sensor cell having a predetermined potential established between the cell electrodes so that the reducing electrode is able to reduce both the nitrogen oxides and oxygen content of the exhaust gas. The current flowing through the sensor cell is measured to determine whether the nitrogen oxides content of the exhaust gas is sufficiently low.

Abstract: A stable oxygen electrode which is in an active state and retains said activity for a long service life. The electrode comprises an electrode carrier and an activated transition metal chelate of 5,14-dihydrodibenzo(5,9,14,18)tetraaza(14)annulene. Said metal chelate is activated by heating in an inner gas atmosphere at a temperature of between about 600.degree. and 1000.degree.C for at least 5 minutes.