Cryostat body wet after liquid nitrogen filling.

Poor vacuum.

Vacuum valve not fully closed.

Vacuum leak.

Pump the vacuum.

Close the vacuum valve.

Pump continuously and inform us.

Cryostat will not receive liquid helium.

No liquid nitrogen.

Helium leak.

Contact between shields.

Fill liquid nitrogen bath.

Pump continuously and inform us.

Return the cryostat to our lab.

Sample cools badly and high flow necessary to stabilise T<50K.

Contact between shields.

Return the cryostat to our lab.

Cold valve blocked.

Cryostat badly flushed.

Reheat to 300K and inform us.

Temperature rises slowly after closing cold valve.

Liquid He pressure valve open.

Leak of liquid He bath to exterior.

Close the Liquid He pressure valve.

Return the cryostat to our lab. for repairing the leak.

Temperature rises rapidly after closing cold valve.

Sample still warm.

Wait for thermal equilibrium of sample and exchanger.

Cooling difficult with temperature oscillations.

Too much exchange gas.

Set T=10K and pump via exchange gas valve to <1mbar.

Sample temperature too high, temperature fluctuations or gradient.

Sample stick too high.

Reposition sample stick.

Temperature too low, fluctuations, pressure rises when heating.

Liquid helium in the anular enclosure (tail).

Close cold valve, set T=10K and wait until the pressure drops to < 2mbar.

Temperature rises for no apparent reason.

Lack of liquid nitrogen and/or liquid helium.

Verify the liquid helium and liquid nitrogen levels, refill.

Sample stick stuck in cryostat.

Air leak into sample well.

Set T=300K, await thermal equilibrium and remove sample stick. DO NOT FORCE AND DO NOT STAY ABOVE THE STICK.

T<10K, cold valve closed, pressure too high (> 5mbar)

Warmvalve open.

Close the warmvalve.