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Lid can rock slightly when the lid nuts are off
It is quite normal for there to be a slight apparent rocking of the Lid when the gap is zero and the lid nuts are
off. This is because the windows are touching and the absence of pressure from the lid nuts allows the Lid to
lift a little. However, if the gap is larger than zero, there should be no rocking. In this case, contact Linkam.
Temperature appears to be several degrees below the displayed temperature
Once the heaters have reached their programmed temperature, it will normally take a minute or so for the heat
to spread evenly throughout the sample. If the sample is not in a liquid state, then it may not be conducting
heat as efficiently as a liquid. Should there be further cause for suspicion that the heaters are not accurate,
there are procedures to verify them and check that their mountings have not been disturbed. In this case, con-
tact Linkam.
Cooling Fault Diagnosis
Ensure that all connections to the stage and Dewar are as shown in the pictures, page 16.
The cooling rate is less than Specified
There can be several causes of this problem, the most likely being that one of the connectors has become
blocked or damaged. Check that each tube is fitted tightly to the connector and that none of the tubing is twist-
ed. This is particularly important in regard to the tubes connecting to the stage, as any constrictions of either
the tubing or the connector will have a drastic effect on the cooling ability of the LNP95 pump. If the connect-
ors and tubing are OK, check that the black capillary tubing to the Dewar flask is not bent or damaged and that
the brass filter from the black capillary tubing inside the Dewar is intact and unblocked. If any damage has
occurred to any of these items then it will be necessary to replace them. If no damage is found, check that the
silver block is not constricted. This can be checked, simply by blowing through one of the coolant pipes.
Check that there is sufficient liquid nitrogen in the Dewar so that the brass filter is beneath the surface. If the
filter is lifted above the surface of the liquid nitrogen water vapour may freeze in the filter and block it. Thaw
the filter to melt the ice and dry it before reinserting into the Dewar.
