6875D Freezer/Mill
1300-87052-1A, REV 1
SPEX SamplePrep LLC
Page 11 of 36
4.4 Lid, Coil Assembly and Gate, LN Sensor
(Cont’d)
lock the Gate during grinding. Always use the proper adapters for mid-size, small vials and
microvials (Section 4.5).
The lid must be completely closed and latched for the 6875D Freezer/Mill to operate. Push the
lid down and hold it down while engaging the bottom part of the latch, and then lock the latch
by pushing its top end toward the cabinet.
The liquid nitrogen (LN) sensor is located behind a shield on the back wall of the LN tub. While
in Auto Fill mode, with the 6875D Freezer/Mill connected to the LN Tank, the unit will add
liquid nitrogen automatically to maintain the proper LN level. In the optional Manual Fill mode,
to prevent overfilling the tub, the unit will sound with a series of
“Beep
s
”
when the proper
operating LN Level is reached (approximately 2 inches (5.1cm) below rim). If the unit is started
and the LN Level is low, the
screen will display status as LOW LN LEVEL (Figure 8). If the LN runs
low during a grinding program the same message will appear
“LOW LN LEVEL”
and the program
will stop. Open lid and fill the tub with liquid nitrogen
until the unit “Beeps”
indicating the tub
has been filled to the proper operating LN level. Close the lid
, “TOUCH
RESUME BUTTON
”,
and
the grinding program will begin where it left off.
NOTE: To keep a Run from being interrupted by low liquid nitrogen levels, use the Auto Fill
mode with LN Tank connected. In the optional Manual Fill mode the unit will not run if
the proper LN level is not maintained. The liquid nitrogen should be topped off when
needed. The Freezer/Mill warranty does not cover damage to the magnetic coils
caused by operating the mill with little or no liquid nitrogen.
4.5 Grinding Vial Sizes, Adapters, and Vial Openers
Large vials (6801, 6871, 6803) are run one per chamber in the 6875D Freezer/Mill, without any
adapter. Large vials can be opened using the 6804 Extractor/Vial Opener, which is part of the
6870L Accessory Package. (Or the optional 6808 Extractor/Vial Opener, available for purchase)
Mid-Size vials are run one per chamber, but the 6887 Mid-Size Adapter must be used with the
6881 and 6883 vials, and the 6888 Adapter must be used with the 6885 vial. The 6887 Adapter
included in the 6870M Accessory Package (6888 Adapter is sold separately). Mid-Size vials can
be opened by the 6804 Extractor/Vial Opener, but only by first installing the 6884 Mid-Size Vial
Adapter. (The 6808 Extractor/Vial Opener with 6808M Mid-Size Vial Adapter Kit, is available for
purchase)
Small vials (6751, 6761, 6771, 6781S) can be run one, two, three, or four per chamber in the
6875D Freezer/Mill. However, the small vials must be used in conjunction with the 6807 Vial
Holder insert for the grinding chamber. The vial holder keeps the vials parallel to each other
and parallel with the chamber, so each impactor moves back and forth in line with the magnetic
field during grinding.
