Zeiss humphrey HFA II-i series Field Service Manual page 130

Adjustment / Calibration
Procedure
1) Set up the tool stand with the mirror tool attached as shown in Figure 4-8. Manually
adjust the mirror so that the mirror surface faces up (towards the top of the bowl) and
extends outward as shown.
2) Raise the chin rest to its upper limit. The chin rest motor will stop (and make a buzzing
sound) when it reaches its upper limit.
From the Calibration main menu, select INTENSITY, then BLUE CORRECTION.
3)
Select MIRROR CENTERING. The turret and detector will be positioned so that they
4)
point downward. A message, "Please Center Calibration Mirror", will be displayed on
screen. (You will perform the mirror centering in step 6 of this procedure.)
5) Use a second small mirror (held in your left hand) to locate the image of the lower
turret and detector housing, as shown in Figure 4-9.
6) Adjust the mirror tool (mounted on the chin rest) with your right hand, so that the
reflected beam of blue light can be seen on the surface of the detector housing as
observed with the hand held mirror. When the mirror tool is correctly centered
(positioned), the blue light spot will be seen at some point on the detector housing, as
shown in Figure 4-9.
NOTE: If you cannot locate the beam of blue light, place your hand between the lower turret
and the mirror tool. You should be able to see the blue light on your hand. Once you have
located the blue light, remove your hand and continue to adjust the mirror tool until the blue
light can be seen on the detector housing.
7) Once the mirror tool is correctly centered, place the bowl shroud over the HFA II - i and
turn out the room lights. Ensure that the room is as dark as possible and that no stray
light enters into the bowl. Select OK.
8) A message, "Please wait, adjusting stimulus position..." will be seen. The HFA II - i is
adjusting the position of the turret so that the maximum amount of blue light can be
sensed by the spot detector. This process takes about 20 seconds to complete. When
complete, you will hear the shutter "tap" on the metal surface beneath the shutter and
the instrument will return to the Blue-Yellow Initialization menu.
Select BLUE INITIALIZATION. A message, "Warming up lamp" will be displayed as
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well as a percent complete gauge. The process takes about 4-5 minutes, and when
complete, the instrument will automatically proceed to the Blue-Yellow Initialization
process.
NOTE: During the lamp warm up (or the Blue-Yellow Initialization process described
below), if the room is not dark enough an error message and a beeping sound will prompt
you to try again.
Field Service Guide
Humphrey Field Analyzer II - i
Confidential and Proprietary
4 - 28 52235C1105