Positive Rod Displacement
This method uses a solid rod to displace fluid as it moves in and out of a cylinder into which material is fed. Metering is accurate with good repeatability as the rod displaces a fixed amount for each stroke. The ratio can be changed by simply replacing one of the rods with a different diameter.
The piston displacement method works by attaching a piston to the end of a rod, with which material is pushed out positively from the cylinder. The size of the piston determines the ratio and dispensing amount for each stroke. The dispensing amount can be set by the movement of this rod during the dispensing cycle.
Precision Gear Metering
This method uses the gear size and rotation speed to determine the ratio and dispensing amount. As such, these factors can be changed very easily by changing the rotation speed. The precision gear metering system provides a continuous flow of material without reloading.