Advanced Instruments 4250, Руководство пользователя

Страница: 80 / 121

11. Replace the head cover and its two attaching screws.
12. Reconnect the power cord and turn the instrument on.
13. Make sure the
Supervisor/Operator keyswitch is in the
Supervisor position while using the SETUP and CALIB menus
(see Figure 7 and Chapter 2 “ Supervisor/Operator Keyswitch ” ).
14. When the operating head rises and “ Press START to Continue ”
begins to scroll across the display, press the START soft key.
15. When the display changes to “ Cryoscope Ready ” , press the TEST
soft key. The display will change to “ Select Test Item ” .
16. At “ Select Test Item ” , repeatedly press the > soft key until the dis-
play reads “ Probe Bin Test ” .
17. At “ Probe Bin Test ” , press START . The display will change to
“ [Start] Ready? ” .
18. At “ [Start] Ready? ” , remove the empty sample tube from the freez-
ing chamber, pipette or measure a sample of probe bin setting fluid
into a clean sample tube, place the tube in the freezing chamber and
press the START soft key. The 4250 will run a special freezing
point test to determine the sample probe resistance and bin number.
NOTE In emergency, H
2
O may be used in place of bin-setting fluid for
this test. The bin number thus determined will be acceptable for
bin-setting though the probe resistance displayed is that at the
freezing point of the H
2
O sample used, and will be different
from that for bin-setting fluid.
19. Record the sample probe resistance and bin number in the Service
Log at the end of the user's manual; then press the STOP soft key.
The display will change to “ Probe Bin Test ” .
20. Press SETUP to enter the SETUP menu, then repeatedly press the
> soft key until the display reads “ Set Sample Bin # ” .
21. At “ Set Sample Bin # ” , press the START soft key. The display will
report the current sample bin number setting.
Advanced
®
Cryoscope Model 4250 User’s Guide
58