Lake Shore Cryotronics 121, User Manual

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18 CHAPTER 3: Operation
When changing to a new range, with the current enabled, the new range
will flash for 3 s before setting the new current. For the user current
range, the instrument will flash “USER” once, and then it will flash the
actual value of the user current twice before changing the output cur-
rent. This allows for the user to select a new range directly without
applying intermediate ranges. There is no wait time when making a
range change through the computer interface. Refer to Chapter 4.
When changing to a new range with the current disabled, the new range
will display for 1 s before the display goes back to displaying “OFF”. The
new range will be stored in the memory so when the current is enabled
the instrument will go to this new range. When reaching the user cur-
rent range “USER” will display once before displaying “OFF”.
Menu Navigation
Range: 100 nA, 300 nA
Default: 100 nA
Interface Command:
RANGE
3.5.3 Polarity Change
The Model 121 allows for the user to switch the polarity of the current by
pressing
+/-. This key will switch the polarity of the output current for
any of the fixed ranges and user current. The +/- key works inde-
pendently for the fixed ranges and user current range. Pressing +/- in a
fixed range will change the polarity of all fixed ranges, but not the user
current. Pressing
+/- in the user current range will only change the polar-
ity of the user current. The instrument will immediately change the
polarity of the current upon receiving a key press.
Menu Navigation
Polarity: Positive or Negative
Default: Positive
Interface Command:
IPOL