Measurement and Control

Bolton, M. S.; Taylor, D. S.

doi: 10.1177/002029407300601001pmid: N/A

A cheap device which can indicate carbon monoxide levels in exhaust emission of internal combustion engines, and hence could be used for adjusting the engine's operating air: fuel mixture ratio, would have widespread application in garages, etc. The instrument described here is sensitive to both unburnt hydrocarbons and carbon monoxide but measures the carbon monoxide to an accuracy well within the tuning capability of most carburation systems.

Asbury, A.

doi: 10.1177/002029407300601002pmid: N/A

The method of design involves three steps:Choose a closed loop system with the aid of contour plots of the performance criteria.Obtain the poles of the open loop inferred by the chosen system.Provide a synthesised transfer function which will correct the actual open loop to the form given by (2).This paper deals with (1) and provides the contour plots for:Time to 90% and to cross over.Time to within 1%.Overshoot and undershoot.Maximum rate.Velocity error constant.Bandwidth.Phase and gain margin.These are plotted against c and k where c is the ratio of real pole abscissa to the real part of the dominant complex poles and k is the ratio of the imaginary to the real part of the complex poles. A preferred region is defined which will be suitable for many industrial applications.