Abstract: A microprocessor controlled precision dispensing system (PDS) introduces an additive into a flowing liquid. A fixed amount of additive is introduced per unit volume of the liquid. The fixed amount can be changed by the user and can be varied as a function of an external parameter. The PDS includes a dispensing device which is actuated by a flow meter. The liquid flows through the flow meter which includes a Hall effect transducer which measures flow rate. The signal from the Hall effect transducer is input into a microprocessor mounted in the dispensing device. The microprocessor controls a stepper motor which drives a crankshaft which drives a reciprocating pump. The release of the additive is correlated to the volume of liquid flow. The dispensing device includes means for selecting the amount of additive to be dispensed per gallon of liquid. For example, the system can be set to dispense an amount from 0-10 ml/gal; this amount can be changed by increments of 0.01 ml.

Abstract: A time release bolus comprises a tubular member and an end cap secured to each other. The tubular member contains an inner bag which is adapted to receive and contain a nutrient or medicament substance. A capsule is provided in the tubular member, and upon fracture thereof, applies pressure to the inner bag. The end cap includes a plug which fits into an open end of the tubular member and a top portion. A passage is provided which leads from the tubular member to the exterior, such that nutrient or medicament can flow from the inside of the tubular member to the outside of the time release bolus. The bolus further includes in the end cap a mesh in the flow path of the substance, the mesh further restricting and controlling the amount of substance which may pass from the bolus to the exterior.