3
2 HARDWARE SETUP
Select a chopper wheel to be installed based on the desired frequency and maximum allowable
beam size.
Number of
Apertures
Frequency
Range
Maximum
Beam Size
2
4 to 140 Hz
32 mm
5
25 to 350 Hz
28 mm
12
60 to 800 Hz
13.7 mm
30
150 to 2000 Hz
4.6 mm
To install a chopper wheel into the chopper head, first loosen the four (4) philips head screws
that hold the cover in place; slide the cover off.
Using a 3/32 hex head wrench, remove the three (3) socket head cap screws and the wheel hub
washer from the center hub of the chopper head.
Insert the chopper wheel in the gap of the photodetectors and reattach the hub washer and
screws.
Reattach the cover and tighten all cover screws.
The enclosed chopper includes a set of apertures that match the beam size to the wheel
aperture. The aperture is inserted into the female flange.
Remove the pan head screw in the flange just above the motor, insert the proper aperture
and replace the pan head screw to hold aperture in place. The correct aperture matches the
maximum beam size. Note that the flange acts as the aperture for the two aperture wheel.
