The filter wheel assemblies are designed to hold up to six 1-inch-diameter samples or filters. Normally, up to five filters are installed with the sixth position left open. FA-448 filter wheels are available with manual or motorized filter selection.

Model FA-448
Manual version which includes a 2-pole stepping motor with integrated filter selection knob as shown in the photograph at right. To select a filter, the user simply rotates the knob. Manual FA-448 filter wheels are easily converted at any time for motorized operation by purchasing the Model FA-448-4 controller.

Mode FA-488-2
FA-448-2 is a motorized six-position filter wheel with a stepping motor and a controller with an RS232 interface for computer-controlled filter indexing. This assembly permits both computer selection of filters and motorized selection using the thumb-wheel control.

Order Sorting Filter Set
AR offers an order sorting filter set designed to eliminate unwanted second order radiation. The set consists of cut-off filters at 320nm, 590nm, 665nm, and 715nm. Typical transmission characteristics for these filters is shown in the graph at right. How Order Sorting Filters Work: Assume you plan to work at a wavelength of 400nm and wish to block second order 200nm light that is contaminating the data. Using the FA-448-1 or FA-448-3 order sorting filter wheels, you would index the 320nm cut-off filter into the beam path. This filter blocks 200nm while transmitting 400nm, allowing only the desired light to reach the detector. The unwanted light is eliminated for improved accuracy.