Ametek ORTEC MOBIUS-B, User Manual, Page: 23 / 28

805709F / 1115 ORTEC
® MÖBIUS™ HPGe Detector Cooling System
17
4) Once the air filter is inserted, push the mesh screen back in the bracket as in Figure 15b.
Figure 15b. Installing the mesh screen.
4.2. EMPTYING AND WARMING THE MÖBIUS
Turn the MÖBIUS rear-panel power switch to the “Off” position, open the fill and vent valves to depressurize the
dewar, and remove the detector/cryostat assembly according to Section 4.5. Then remove the LN2 with one of the
following methods:
●
Slower — Obtain a cylinder of high-purity, oil-free, dry nitrogen gas (not “house” nitrogen). Connect to the fill
valve and stream at very low pressure to gently boil off the LN2 and evaporate any water from inside the
dewar.
●
Faster — Use the ORTEC Model WD/30 LN2 withdrawal device (Figure 16) to transfer the LN2 to another
dewar. The WD/30 uses the pressure buildup in the dewar vapor space to push the LN2 up the tube and out a
transfer line. Attaching the WD/30 requires removing the fill collar. Contact ORTEC for more details.
Figure 16. ORTEC Model WD/30.
CAUTION Do not tip the MÖBIUS and pour the LN2 out of the fill collar! Doing so will damage the cooler and may
breach the dewar’s vacuum seal.