laboratory evaluation of test apparatus and techniques for investigating spray deposit and drift in crack and crevice treatments

The addition of petcock, air regulators, air pressure gauges, and other modifications to a multi-teeject nozzle and a b&g sprayer is employed to investigate the deposit and drift of insecticides in crack and crevice treatment. Rate of application, insecticide concentration, tank pressure, and air turbulence affect insecticide concentration on the outside of the crack. Width of the crack strongly influences deposit along the crack interior. The modified apparatus proves accurate and sensitive to changes in crack width and depths.