Samenvatting
This report describes operating and maintenance experience with the Fischer and porter punched-tape counter under tropical conditions. It is based on the results of a two- year study by staff from the laboratory of 25 counter installations in Kenya. The report describes the special installation procedures required for earth and gravel roads. An analysis is given of the life of detector tubes and batteries and of the causes of counter breakdowns. The need for an underground method of detecting vehicles is clearly indicated by the difficulties experienced with conventional surface-laid pneumatic-tube detectors. The problems to be overcome in developing a viable system are discussed. (Author/publisher)