Advanced Bilirubin Stat-Analyzer BR2, Руководство по обслуживанию, Страница: 40 / 69

The Advanced® Model BR2 Service Manual
40
Use this procedure to minimize the Zero
adjustment that may be required after switch-
ing from Total to Direct during the Operating
Procedure..
Tools needed: Flat-bladed screw-driver.
Warning-Hazardous Voltage
Warning-Internal components may
be damaged by static electricity.
1. Shut off and unplug the BR2.
2. Remove the four screws from both sides
of the BR2 and pull the instrument cover
straight up and off.
3. Plug in and power the instrument careful-
ly so that you do not contact the AC line
voltage between the fuse holder and
power transformer.
4. Rotate the ten-turn Zero control knob all
the way either clockwise or counterclock-
wise, then exactly five turns back to the
center.
5. Make sure that toggle switch S2, if
installed, is at NORMAL, and selector
switch S3, if installed, is at +15. Adjust
R38 (the 540 GAIN potentiometer next to
the large, square IC7 near the left center
of the Main board) for a readout of exact-
ly 00.0.
6. Press the Direct button. Adjust R43 (the
SET DIRECT potentiometer at the left
front of the Main board) for a readout of
exactly 00.0.
7. Shut off and unplug the BR2 before
replacing the instrument cover.
Refer to the User’s Guide for warm-up, cali-
bration and operating instructions. Remember
to allow 15 to 30 minutes warm-up before
recalibration.
Direct Zero Adjustment Procedure