Elf for electronic linear flow control of variable speed ground ULV applications.

The Elf device delivered the appropriate ground ULV rate at variable road speeds ranging from 4 to 21 mph (6 to 32 kph), and shut off automatically at higher and lower speeds. The system is designed to be compatible with vehicles equipped with digital as well as standard speedometers and can be calibrated at any speed within its operating range. Although not used in these studies, Elf has a distance calibration feature designed to enhance the accuracy of the transducer and thus to yield greater flow precision than could be achieved with the transducer alone.