Zeiss humphrey HFA II-i series Field Service Manual page 137

Humphrey Field Analyzer II - i
Special Tools/Equipment Required
Tool Stand
P
Fake Eye
P
Prerequisites
Before performing IR LED intensity, check/adjust the following:
1) Trial Lens Holder Alignment (4.9.6)
2) Camera Focus (4.9.7)
3) Bowl IR LED/Mirror (4.9.8)
Perform the Camera Position/Size Calibration as previously described in this
4)
service bulletin.
Procedure
Models 720i
1) From the Calibration main menu, select CAMERA INTENSITY.
2) Set GAIN WITH LENS HOLDER to 35, and STORE it.
3) Set GAIN WITHOUT LENS HOLDER to 35, STORE it, and select DONE.
Models 740i and 750i
1) Dim the room lights and turn down the brightness on the CRT. (This greatly improves
your ability to distinguish small differences in illumination in the CRT image.)
2) From the Calibration main menu, select, CAMERA, INTENSITY.
3) Install the fake eye on the tool stand, and slide the tool stand onto the instrument
chinrest. Push the tool stand forward slightly on the chinrest so that the metal tips on
the Tool Stand Alignment Adaptor make contact with the headrest (Figure. 4-10). This
is the position the tool stand should be in when performing the procedure.
4) Raise and position the trial lens holder against the right angle bracket of the fake eye.
The right-angle extension on the fake eye assembly will press against the trial lens
holder and position it correctly (Figure 4-11). (Set the chinrest height so that the right-
angle extension touches the trial lens holder at about the 0 - 0 level on the trial lens
holder scale.) Verify that there is a central reflex indicating that the reflex LED in on.
NOTE: Once you have the trial lens holder set, do not move it.
5) Center the fake eye to the cross in the video insert.
52235C1105
Confidential and Proprietary
4 - 35
Adjustment / Calibration
Field Service Guide