Advanced Instruments 4250, Руководство пользователя

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about .06 inches (1.5 mm) away from the sample probe.
5. After any probe or stir/freeze wire position adjustment, check and
adjust the stir/freeze amplitude, as necessary, as recommended in the
section “ Stir/Freeze Amplitude Adjustment. ”
6. After making any probe and/or stir/freeze wire adjustments, check
the instrument calibration and recalibrate as necessary
.
Alternate method of probe and stir/freeze wire alignment
using a sample tube containing 2-mL of water:
1. Pipette a 2-mL sample of H
2
O or any of the standards into a sample
tube. Then hold the tube up on the mandrel in the position shown in
Figure 11. Note in which direction the tip of the probe must be
moved (if any) to perfectly center its black sensor bead in the sample
volume. Remove the sample tube.
2. If vertical adjustment of the probe tip is necessary to center the black
bead in the 2-mL sample volume, loosen the probe setscrew (Figure
10, Item 6), then manually raise or lower the probe within the man-
drel. Retighten the setscrew gently (overtightening will crack or dis-
tort the thin plastic wall of the mandrel). Recheck as described in
step 1 above.
3. If horizontal adjustment is necessary to center the black bead in the
sample volume, bend the metal probe stem gently in the required
direction by hand. Recheck as described in step 1 above.
4. Check and adjust the stir/freeze wire position according to the rec-
ommendations in Figure 9.
5. After any stir/freeze wire position adjustment, check and adjust the
stir/freeze amplitude, as necessary, as recommended in the next sec-
tion “ Stir/Freeze Amplitude Adjustment. ”
Stir/freeze amplitude adjustment
The stir and freeze vibration amplitudes are affected by the probe,
stir/freeze wire and mandrel positions. If the one-second freeze pulse is
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Troubleshooting & Service