Clayton Manufacturing Company

Scans Associates, Inc.

Leland P Tinkham

Edwin Lee Cline

Vernon G Converse, Iii

Modal test method and apparatus is described for use in automotive engine plants, vehicle inspection stations, diagnostic centers, etc., for quickly, accurately and repeatably measuring the principal air contaminants; i.e., carbon monoxide (CO) and hydrocarbons (HC) in engine exhaust gas emissions. Quantitive measurement of oxides of nitrogen (NO.sub.x) and oxygen (O.sub.2) may also be measured if desired. While O.sub.2 is not an air contaminant, a measure of its concentration in the exhaust gas has diagnostic value. The engines are tested at prescribed modes of operation (usually three; high cruise, low cruise and idle) at which emission-related engine malfunctions, if they exist, are most likely to be exposed. CO and HC (NO.sub.x and O.sub.2 if desired) evaluations are made at each test mode and may be recorded on a 'report card.' The measured test values of the air contaminants are compared at each test mode with prescribed permissible values either automatically or manually. For example, the measured values may be recorded on a report card which includes the permissible values. An excessive value of the measured air contaminants for any prescribed mode indicates an emission-related malfunction and warrants rejection. Adjustment or repair to correct malfunctions is facilitated by providing 'truth chart' having a reject pattern matching that on the report card and a written statement of the probable defects and the recommended repair guidelines to enable a mechanic to quickly correct the malfunction.

Method and apparatus for quickly evaluating engine exhaust gas emissions

A method and apparatus for hot testing on a production basis, automobile engines as they come off the assembly line for performing a final check on such engines before they are installed in the automobile. The engines are tested for exhaust emissions at three points or KEY MODES of operation at which emission related engine malfunctions are most likely to appear. These points of operation are high cruise, low cruise, and idle. The engine, after it comes off the assembly line is placed in a production test stand wherein the connections for water, oil and exhaust are made, the engine is started, accelarated to the high cruise speed, and allowed to warm up for a predetermined time, after which time, measurements of hydrocarbons and carbon monoxide are taken and an appropriate indicator light lit to indicate that the engine either is within limits at this speed, or does not pass for some reason. The same procedure is followed in the low cruise and idle speeds. If one or more of the indicator lights show a reject condition, the engine is automatically removed from the production test stand and routed to a repair shop for further testing.

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Desert Hot Springs, CA, United States of America

Leland P Tinkham