M74050
1/4M IMAGING SPECTROGRAPHS
40
11.4 GRATING INSTALLATION
Each grating comes mounted and aligned on a grating mount. For most applications, there is no
need to adjust this grating holder. Refer to the general warnings and precautions section of this
manual regarding the care and handling of diffraction gratings. Note that only one grating should
be replaced at a time.
Procedure:
1. Using the MS260i Hand Controller or utility software, close the shutter.
2. Command the MS260i to go to the grating that is to be replaced.
3. Go to wavelength 0. The grating facing the collimating mirror is the grating that was selected.
4. Turn off the power switch on the spectrograph and unplug the instrument from the electrical
mains.
5. Remove all screws holding the spectrograph cover in place, then remove the cover.
6. Two long screws, one on each side of the grating, must be removed. Used a screwdriver to
loosen these screws.
7. Grasp the sides of the grating mount with one hand and firmly pull the grating up and out of the
instrument. Pull in a direction parallel to the grating face
– not directly upwards. During this
process, ensure the other grating or gratings do not move. They should be held in place using
a free hand by grasping or pressing down on the remaining grating holder(s).
8. Carefully uncover the new grating to be installed and set aside.
9. Use the cover from the new grating to protect the grating that was just removed.
10. Install the new grating onto the grating platform and ensure the new grating is parallel to the
other gratings. The grating should fit into a pin located on the platform.
11. Push the new grating up against the large central pin in the middle of the platform.
12. Re-install the long screws that held the previous grating in place. Use only firm finger pressure
to tighten them. Do not tighten one completely while the other screw is loose. It is best to
alternate tightening between the two screws. Ensure the screws line up parallel with the grating
face.
13. Replace the cover on the spectrograph and secure using all screws provided. Failure to use
all hardware will result in increased stray light.
14. Connect the spectrograph to the electrical mains and switch on the power.
15. Follow the procedures outlined in this manual to determine the grating factor and any offset.
16. Use the Mono utility software to update the calibration parameters as needed.
17. It is suggested to verify the calibration factors and offsets of the other gratings that were not
replaced, as they may have accidentally been moved during this process.