Hitachi Microscope & Magnifier S-4800 Manual De Usuario

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The signal intensity of the lower detector significantly decreases at short WD conditions. It is 
recommended to use the lower detector at a WD of 7mm or longer. 
 
(3)   Mixed Signal of Upper and Lower Detectors: 
The upper and lower detector signals can be mixed to show characteristics of both detectors. 
The intensity of this signal does not vary much for a change of WD.   
   
When the U/D Variable is shown with blue color, the ratio of Upper and Lower detector gain 
follows the contrast settings those previously adjusted in Upper and Lower mode individually. 
You may control the mixing ratio of upper and lower detector signals. 
When it is shown with light gray color, both detectors have the same gain. In this case, the 
ratio of two signals are changed automatically depending on WD position, and therefore the 
signal of the upper detector is dominant at shorter working distances, while that of the lower 
detector is outstanding at longer working distances.     
 
NOTE: If 
the 
ABCC Link check box in the Column tab of the Setup dialog window has been 
checked, ABCC will start automatically when detector selection is changed. Image 
brightness will be adjusted to adequate value. 
 
 
3.5.1.1    Secondary and backscattered signals and their Characteristics   
 
The following figure shows detectable signals using the S-4800. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  SE stands for secondary electron signal.    BSE-L means backscattered electron signal 
generated at low angles from the specimen.    BSE-H backscattered electron signal generated at 
high angles from the specimen.    Each of these electron signals has characteristic information of 
the specimen.    You may obtain the best images of your samples and your specific purpose of 
applications by choosing one or mixing of the signals.       
The following table shows general characteristic of these signals. 
 
Primary electron
BSE(Lower)
Specimen 
SE 
BSE-L
BSE-H
(Upper detector)