Princeton 4411-0087 Manuale Utente

36 

ST-133 Controller Manual 

Version 3.B 

 

Hint: Overhead fluorescent lights produce a mercury spectrum. Use a white card 
tilted at 45 degrees in front of the entrance slit to reflect overhead light into the 
spectrograph. Select 435.833 as the spectral line. 

3.  Set the slit to 25 µm. If necessary, adjust the Exposure Time to maintain optimum 

(near full-scale) signal intensity. 

4.  Slowly move the detector in and out of focus. You should see the spectral line go 

from broad to narrow and back to broad. Leave the detector set for the narrowest 
achievable line. You may want to use the Focus Helper function (

Helper…) to determine the narrowest line width: it can automatically locate peaks 
and generate a report on peak characteristics during live data acquisition (see the 
WinSpec/32 on-line help for more information).  

Note that the way focusing is accomplished depends on the spectrograph, as follows:  

•  Long focal-length spectrographs such as the Acton 300i: The 

mounting adapter includes a tube that slides inside another tube to move the 
detector in or out as required to achieve optimum focus.  

•  Short focal-length spectrographs: There is generally a focusing 

mechanism on the spectrograph itself which, when adjusted, will move the 
optics as required to achieve proper focus.  

•  No focusing adjustment: If there is no focusing adjustment, either 

provided by the spectrograph or by the mounting hardware, then the only 
recourse will be to adjust the spectrograph’s focusing mirror. 

5.  Next adjust the rotation. You can do this by rotating the detector while watching a 

live display of the line. The line will go from broad to narrow and back to broad. 
Leave the detector rotation set for the narrowest achievable line.  

Alternatively, take an image, display the horizontal and vertical cursor bars, and 
compare the vertical bar to the line shape on the screen. Rotate the detector until the 
line shape on the screen is parallel with the vertical bar.  

Note: When aligning other accessories, such as fibers, lenses, optical fiber adapters, 
first align the spectrograph to the slit. Then align the accessory without disturbing the 
detector position. The procedure is identical to that used to focus the spectrograph 
(i.e., do the focus and alignment operations while watching a live image). 

This completes First Light. If the system functioned as described, you can be reasonably 
sure it has arrived in good working order. In addition, you should have a basic 
understanding of how the system hardware is used. Other topics, which are important 
under certain conditions, are discussed in the following chapters. See the appropriate 
application software manual for information on using the software to control the system.