Kv Compensation - GE Alpha RT 32551 Installation Instructions Manual

5 Setups, alignments and adjustments
8 Go back to service mode and make two exposures with semi-
automatic (A) mode 27kV so that very long exposure time (four times
longer than exposure time for 40 mm Acr = for example 4-5 sec.) and
very short exposure time (3 of exposure time for 40 mm Acr = for
example 250-300 ms) are achieved.
9 Develop the films and record the optical density of the films (=O.D).
10 Select the adjustment direction of 'S1' (affects the compensation
slope at exposures shorter than rotation point 'P') and 'S2' (affects the
compensation slope at exposures longer than rotation point 'P') from
the table below.
r1<1
r1>1
r2<1
r2>1
Table 5.10 O.D. corrections
'S1' and 'S2' can have values 0, 50, 100, 150...up to 700. The maximum
compensation is 140% or 60% of O.D. in 'P' (rotation Point).
11 Enter the #64 AEC program. Press kV+ until the thickness
compensation parameter 'c' is reached.
12 Press Autorel to scroll the 'S1' parameter in the kV display. Use
Den+/- buttons to change the value. This parameter affects the
compensation slope at exposures shorter than rotation point 'P'.
13 Press Autorel to scroll the 'S2' parameter in the kV display. Use
Den+/- buttons to change the value. This parameter affects the
compensation slope at exposures longer than rotation point 'P'.
5.2.18

kV compensation

The kV compensation is performed with both filters (Mo/Rh) and all
cassette tunnels (Bucky/cassette holder/magnification tunnel) separately.
DO NOT change the gain parameter anymore.
1 Enter service program 64.
2 Proceed to loop in AA- and A-modes.
The Control Panel will display:
– kV screen of the Control Panel: current kV selected
– Density Correction on mAs-screen of the control panel: + 1.00
(default)
3 Adjust for each station (a, b, c) in both modes.
86
too light O.D.
increase S1
decrease S1
decrease S2
increase S2
GE Healthcare
too dark O.D.
decrease S1
increase S1
increase S2
decrease S2
32551-IMG rev 6