2 Operational Procedures
F
ILL AND
I
NSTALL THE
D
EWAR
Dewar Precautions on the facing page
1. Fill the Dewar with the analysis bath liquid (such as liquid nitrogen) to no higher than 1 in.
(2.5 cm) from the top for a large Dewar or no higher than 3/4 in. (2 cm) from the top for a
smaller Dewar.
Incorrect fluid levels can lead to measurement errors. Check the level of the bath
liquid before each analysis.
2. Check the level of the analysis bath liquid. For best results, if the Dewar has not been used
for a while, allow approximately 30 minutes for the temperature of the Dewar to stabilize
with the bath liquid, then recheck the level of the bath liquid. Add additional liquid if
necessary.
3. Slide the Dewar cover to approximately 7.5 cm (3 in.) from the sample port nuts to ensure a
proper seal on the top of the Dewar.
4. Place the Dewar on the elevator. A Dewar support is not necessary for the larger Dewar
used with the Gemini 2390t. Place the Dewar directly on the elevator.
5. Close the safety shield on the front of the analyzer.
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Gemini VII Keypad Operator Manual
239-42801-01 (Rev E) — July 2021
