Service manual

LUMISCAN ACR-2000 READER SERVICE MANUAL - SECTION 5.0 SERVICE ADJUSTMENTS
5-8
5.3.21.5 Visually observe the laser sweep. If the laser sweep extends 1.5 +/- 0.5 inches past the light
Collection Chamber opening on the left side and 2.5 +/- 0.5 inches past the light Collection Chamber opening
on the right side, then proceed to 5.3.21.6. Otherwise, go back to step 5.3.21.2.
5.3.21.6 The room lights should be dim and the unit covered to minimize stray light.
5.3.21.7 Place the 14” Linearity Adjust Pattern (P/N 0070-966) in the input slot with the vertical lines
facing the unit and the widest red bar towards the abort button.
5.3.21.8 From the “tools” directory, enter LNADJDT /D at the command prompt. Enter the Serial
Number of the reader. Press <Enter> to continue. When prompted for Lines to Skip, press <Enter>.
When prompted for Black / White Threshold, enter 1200.
5.3.21.9 Use R59 to adjust the Sum of Deltas to nominal.
5.3.21.10 Use R58 to adjust the Distance to first edge to nominal.
5.3.21.11 Proceed to 5.3.10.
5.4 PMT Sub System
This section provides the method of adjusting the System for alignment or after replacement of the DACQ
PCA, PMT tubes, PMT preamp or Ref Amp.
NOTE
Allow the LUMISCAN to warm up for at least 30 minutes prior to making
any adjustments.
CAUTION
When making these adjustments, be aware that the Photomultiplier tube is EXTREMELY sensitive to
light. When you remove the cover, use a photographic dark cloth to prevent ambient light from
damaging the tube or effecting your density adjustments.
5.4.1 PMT Preamp Offset Adjustment
1. Disable the PMT high voltage. This is most conveniently done by disconnecting the AUX
I/O cable on top of the DACQ PCA..
2. Set the DVM for the mV range. Measure at TP9 on the DACQ PCA. If the voltage is 0mV
+/- 0.1 mV, go to 5.4.3. Otherwise, proceed to step 3.
3. Remove the Front Enclosure from the digitizer.