User Manual

11-4 Needle Sensor
Operation
Both the NS Series Needle Sensor and the NSZ Series Needle Sensor work with FmNT.
The software on the dispensing system is configured at the Asymtek factory to work with
either type of Needle Sensor.
Theory of Operation
The dispensing head lowers the dispensing needle into the Sensor’s needle slot, then passes
it in front of two light beams, one for the X-Axis and one for the Y-Axis. When the needle
breaks a beam, a coordinate is recorded. By detecting the needle’s X and Y coordinates,
Fluidmove establishes the center of the needle. After that, the software aligns the needle
with one of the beams and raises the dispensing head until the needle no longer blocks the
beam. This locates the tip of the needle, which is the Z-Axis coordinate.
On systems with an NSZ Series Needle Sensor, the Height Sensor determines the Z-height
of the needle tip by descending upon the Load Cell. When the dispensing head touches the
needle tip to the Load Cell, the height of the needle tip is recorded by the Fluidmove
software.