Oxford Instruments MicrostatHe - Appendices; Electrical Connections on the Cryostat

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Microstat He Manual

Appendices

9.1 Electrical connections on the cryostat

The standard cryostat is fitted with a 10-pin seal near the top of the cooling unit. This is used for the connection to the cold finger. The

seal is held in place by a black nut - do not remove it unless you need to gain access to the wiring. The heat exchanger is fitted with

a Rhodium-Iron resistance thermometer (four-wire measurement) and heater. The wiring configuration of the 10-pin seal is given in the

table below:

Pin Function

A Heat exchanger heater

B Heat exchanger heater

C Heat exchanger sensor (V+)

D Heat exchanger sensor (V-)

E Heat exchanger sensor (I+)

F Heat exchanger sensor (I-)

H Spare

J Spare

K Spare

L Spare

9.1.1 Checking the wiring

A resistance meter can be used to check the wiring of the cryostat - the following readings should be expected across pins:

Pins Nominal resistance

A - B 40 Ω approx.

C - D

30 Ω approx.

C - E < 15 Ω

C - F 30 Ω approx.

E - F 30 Ω approx.

A - C > 1 MΩ

A - ground > 1 MΩ

C - ground > 1 MΩ

9.1.2 Additional Wiring - LX10 connector

An additional 10-pin connector, fitted to the top plate of the cryostat, is wired to terminals located just above the sample holder.