ANLAGE ZUR REGELUNG EINER DURCHFLUSSMENGE

A liquid fertilizer or plant protecting liquid is discharged at a specific liquid output rate (amount per unit area) by apparatus carried by a tractor and trailer. A mass flow-meter 6 is arranged in a main pressure conduit leading to a nozzle frame 25. The output of the meter 6 is connected to the write-in input of a counter 10 through a division circuit comprising counting trains 9, 19 and selector switches 20, 21. The erase input of the counter 10 is connected to an odometer 3. The output of the counter 10 is connected to the write-in input of a store 11 having a clock-pulse input connected to the output of the odometer 3. A comparator 12 has one input connected to the output of the store 11 and another input connected to a reference signal unit 13. The comparator output is connected through a three-position switch 14, 15 and a limit switch 22 to the input of a controlling unit 27, consisting of a servo motor 5 controlling a valve 4 in the main pressure conduit.