Abstract: Method and apparatus for automotive tire condition and other article assessment is based upon radiation analysis of a rotated tire. Analysis of reflected radiation on the basis of intensity sensing provides a measure of tread depth and sidewall profile, together with tread location and other data. By positional analysis of the tread depth locations there is provided complementary information on the tread wear pattern. Sidewall profile determination enables identification of other tire condition factors. Tread depth and sidewall profile are also determined by laser or other radiation line image displacement techniques and a mounting system is provided for the apparatus enabling determinations to be made without the use of a roller bed. Proper positional alignment of the wheel to the apparatus is determined by means of a reference datum derived from reflected radiation within the apparatus.

Abstract: A method of analyzing exhaust gas emissions from an internal combustion engine is modified by the provision of a data process or connected to an exhaust gas analyzer and adapted to monitor changes in exhaust gas concentrations and to identify changes indicative of the state of operation of a catalytic system provided in the engine exhaust delivery system. The catalyst-on condition is identified by reference to the characteristic shape of the plot of the gas concentrations against time. Similar identification of catalyst-off conditions is provided by corresponding analysis of concentration changes and concentration values. The system can distinguish between various causes of the catalyst-off condition.