Abstract: A method and apparatus for testing automotive electronic control units and batteries and other equipment for identification and performance purposes utilizes neural networks to effect waveform analysis on a digitized signal. Identification of electronic control units is by means of correlation of resultant waveform data with corresponding data on known units. Battery testing is by waveform analysis of the battery current during transient connection of a load by a transistorized switching circuit. In both cases the method of testing includes a network learning stage and an ensuing recognition test routine for characteristic waveforms.

Abstract: Method and apparatus for freon and other refrigerant matching, particularly for servicing of air conditioning systems for automotive applications. The matching process is based upon the comparison of resistance or infrared absorption or other data readings of a gas-sensing resistance or infrared absorption or other transducer applied to the refrigerant fluid under test and corresponding data from reference refrigerants.

Abstract: A method and apparatus for analysis of engines analyzes digitized input signals from, for example, engine injectors and compares this digital data with the corresponding values of a digitized template or comparison signal. Compliance or divergence between the digitized signal values is indicated in bar graph form.

Abstract: A method and apparatus for analysis of particulate content of gases, applicable to the quantitative and qualitative analysis of vehicle engine emissions, includes sampling, removing particles and analysis of the removed particles. Sampling is effected by electrostatic precipitation using a catalyst-coated piezoelectric crystal. The analysis of the removed particles is effected by heating the crystal in an oxidizing atmosphere to oxidize the deposited particles. Connection of the crystal to an oscillation circuit enables the frequency of oscillation of the crystal to be monitored. Changes in the frequency of oscillation are interpreted to provide quantitative and qualitative analysis of particles deposited and subsequently oxidized.

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.

Abstract: There is disclosed a method and apparatus for testing inflated vehicle tires to determine internal physical characteristics such as tire pressure. The apparatus includes a waveform transceiver for subjecting a tire to be tested to a transmitted waveform and for transmitting an ultrasonic waveform from a location external to the tire under test and for receiving the ultrasonic waveform from a tire under test at a location external thereto; and a processor for interpreting the received waveform with reference to the decay or attenuation of the amplitude of the waveform with time to provide a measure of the internal physical characteristic.

Abstract: A method and apparatus for instantaneously measuring the level of carbon dioxide (and other gases) in automotive combustion exhaust analysis is provided in the form of a portable battery driven roadside diagnostic instrument in which the CO.sub.2 level is measured by a calorimetric technique utilizing light as the energy source and a piezoelectric bimorph to vibrate a single fiber-optic element to multiplex between two fiber-optic receptors delivering the light to a measurement cell and a reference cell. The measurement cell comprises a salt of an acid-base indicator dye which provides proportional color change on contact with CO.sub.2. The dye is supported on a polymetric film in the cell.

Abstract: Method and apparatus for non-contact evaluation of wheel alignment for vehicles utilizes laser-based range-finders mounted at locations between which the vehicle is driven for test purposes. Range-finding at three locations on the wheel enables wheel attitude to be determined. Locations are chosen so that range-finding is carried out where a significant contour in the wheel assembly occurs, thereby enabling a clear and characteristic signal to be obtained from relatively simple apparatus.

Abstract: A method and apparatus for analysis of brakes in automotive vehicles, and related aspects of engine performance and like applications, senses heat energy which is generated internally of an article to be analysed. Spot-type infra-red thermometers are employed to sense localised temperature elevation produced by brake application from a remote location using visual positioning guides to enable the spot zones sensed to be accurately located on, for example, wheel nuts/studs, which provide a thermal transfer route from the brake drums or discs. Analysis of the thermal data from the sensors includes a peak detect-and-hold function to avoid the need for maintenance of accurate alignment of the sensors. Comparison of the thermal data enables detection of braking imbalance.

Abstract: Gas analysis apparatus particularly applicable to the quantitative monitoring of individual gas components in automotive exhausts, and providing this function in a rapid-response and hand-held, low power consumption format, comprises an array of electrically responsive solid-state sensors to which the mixture of automotive gases to be analyzed is simultaneously fed. Monitoring the electrical response of the sensors enables a substantially instantaneous determination of the quantitative presence of individual components of the gas mixture.

Abstract: Method and apparatus for engine and rotary machine analysis provides a vibration sensor adapted to produce a plurality of superimposed waveforms corresponding to engine or machine operating parameters including rotational speed. The signals are transmitted by an RF transmitter/receiver system in analogue modulated form to a data capture and analytical function unit utilising a software sub-system in which a power spectral density plot is produced containing a signature characteristic of the engine or other machine under test. This signature is recognised by a signature detect algorithm which can recognise and trace the signature across the frequency spectrum covered by the apparatus so as to provide a continuous tachometric function not requiring the filtering-out or other removal of irrelevant data. A diagnostic function arises from detection of the presence of additional harmonic peaks within the signature.