Advanced Instruments 4250 User Manual

The Advanced
®
Model 3250/4250 Service Manual
Block Bin Setting
1. Turn off the power and unplug the instru-
ment. Remove the cover and record the
block probe bin number located on the
block probe wire.
2. Replace the cover. Plug in the instrument
and turn it on. If there is a Supervisor/
Operator keyswitch, turn it to the
Supervisor position (if required).
3. At “Press START to Continue”, press
SETUP.
4. At “Select Setup Item”, press < or > to
select “Select Block Bin #”, and then
press START.
5. Enter the correct number and then press
ENTER twice.
6. Press STOP to exit the menu.
Recalibration will be required.
Stir Amplitude
1. Turn on the instrument. If there is a
Supervisor/Operator keyswitch, turn it to
the Supervisor position (if required).
2. Press SETUP. Press < or > to select “Set
Stir Amplitude”, and then press START.
3. Watch the vibration blur at the tip of the
stir/freeze wire. If the amplitude is not
within the range specified below, press >
to increase the amplitude, or press < to
decrease the amplitude. (The default is
100, but your value may differ.)
3250: The stir wire movement should be
no wider than the width of the
sample probe.
4250: The stir wire movement should be
twice the width of the sample
probe.
4. If using a glass sample tube, check the
setting by placing a sample (water or
standard solution) in position on the
probe. If bubbles form in the sample, or
if the stir wire hits the tube, the current
setting is too high and must be adjusted
downward.
5. When the setting is correct, record the
new stir amplitude number for your
records, and press ENTER.
6. At “Set Stir Amplitude”, press STOP to
return to “Osmometer (or Cryoscope)
Ready”.
Note: Stir wire movement should be stable.
If movement has erratic amplitude,
driver transistor PCB520 may need
replacement. Use an oscilloscope at
J9-1 to verify the presence of a clean,
square wave (see Stir Driver Noise
procedure).
Display/Printer Test
1. Turn on the instrument. If there is a
Supervisor/Operator keyswitch, turn it to
the Supervisor position (if required).
2. Press TEST. Press < or > to select
“Display/Printer Test”, and then press
START twice.
A continuous string of characters and
numbers should scroll across the display,
and a single string of the same characters
and numbers will be sent to the printer.
If not, check your connections and try
again. If you continue to have a problem
and the instrument is working otherwise,
the printer or display may need to be
replaced (see Replacement Instructions
for additional information).
3. Press STOP twice to end the test and exit
the Test menu.
51

Advanced Instruments 4250 Specifications

General

Brand	Advanced Instruments
Model	4250
Category	Medical Equipment
Language	English