Advanced Instruments 4C3, User Manual

Page: 83 / 139

NOTE In emergency, H2O may be used in place of probe bin
setting fluid for this test. The bin number thus determined
will be acceptable for bin setting though the probe resis-
tance displayed will be that at the freezing point of the
H2O sample used and will be different from that at a freez-
ing point of -0.093°C.
On entry, the probe bin test will display “ [START] Ready? ”.
At “ [START] Ready? ”, press the START button. The 4C3 will run
a special freezing point test to determine the sample probe resis-
tance and bin number.
“ Cooling Sample ” will be displayed (as in a normal test) until the
sample probe resistance reaches 4990 ohms. Then the test proceeds
normally except that the display is in ohms rather than millidegrees.
At the end of each test, the final display will be the test result in
ohms and the sample probe bin number (e.g., “ 12345.67 Ohms Bin
10 ”).
A test in progress can be stopped by pressing the STOP button.
Another test may be run by replacing the sample and pressing
START again. At a specific freezing point, each probe has a unique
resistance which should vary very little from test to test. Therefore,
the results of this test may be used as a troubleshooting aid, in con-
junction with the sample probe checks described in section H.
Record the sample probe resistance and bin number in the ser-
vice log at the end of this user’s guide (and/or other convenient
location); then press the STOP button. The display will revert to
“Probe Bin Test” .
Press SETUP and use the procedure described in Chapter 1 to reset
the sample probe bin setting as necessary.
Note that re-calibration is required each time the sample probe is
replaced and/or the sample probe bin number is reset.
61
Troubleshooting & Service