Filter Wheel

Following the aperture wheel the light passes through a filter. The filters are used to select the proper order one is interested in observing before the light is passed to the grating and into the body of the spectrometer. A list of the currently available filters is given below. To command the filter wheel to a position one types a command of the form ``filt to <name>'' (for example filt to k2) in the instrument control window.

Filter Wheel Positions

filt to <name>

Name	Durant	Motor Step	Comment
k+	000	1000	2.00-2.3$\mu$m
j	125	3250	1.15-1.38$\mu$m
blank	187.5	4375	blank between positions
h	250	5500	1.42-1.85$\mu$m
k2	375	7750	2.03-2.46$\mu$m
dark	500	10000	Dark Position
ij	625	12250	.92-1.13$\mu$m
pk50	750	14500	PK50 (Red blocker for X-disp)
lm	875	16750	3.00-5.50$\mu$m