Performance of Agricultural Vehicle Cabs pressurised against Pesticides—Aerosol Testing Method

A method for determining the efficiency of a vehicle cab for agricultural tractors with respect to an aerosol has been developed. This method has been implemented for measuring the efficiency of two cabs differing in their filtration system (medium-and high-efficiency filters) and ventilation designs. For the cab equipped with the high-efficiency filter, the measured cab efficiency is corrected from aerosol internal source. Results obtained for the cab fitted with a medium performance filter revealed an efficiency higher than the efficiency of the filter itself. This increase in efficiency, confirmed by the modelling study, is achieved by partially recycling the air through the filter. Results obtained for the cab fitted with a very high performance filter were the reverse, in as much as the efficiency is lower than the efficiency of the filter itself, in this case. In the latter cab, air was not recycled through the filter and the reduction in efficiency was attributed to leakage from the filter housing. Finally, field determination using a fluorescent tracer of the latter cab efficiency with respect to the aerosol generated during pesticide spraying showed a marked reduction compared with the laboratory-established value. This reduction was attributed to the cab door opening phases during treatment.