Lake Shore Cryotronics 121, User Manual

Page: 26 / 62

16 CHAPTER 3: Operation
3.3 Front Panel Description
The Model 121 has a 6-digit LED display capable of showing both
numeric and character data. In normal operation, the display shows the
output of the current source. The four annunciators on the lower right
hand side of the display indicate the units of the current and whether
the instrument is detecting voltage compliance. There are also four keys
that allow for manually changing the range, polarity, or disabling the
current source output.
3.3.1 Keypad Definitions
The keypad for the Model 121 consists of four keys as described in TABLE
3-1.
3.3.2 Display Annunciators
Display annunciators include symbols for units of current and voltage
compliance.
Key Function Refer to section
+/-
Allows the user to change the polarity of the output
current
section 3.5.3

Allows the user to increase the current range section 3.5.2

Allows the user to decrease the current range section 3.5.2
Allows the user to enable or disable the output current section 3.5.1
TABLE 3-1 Keypad definitions
Annunciator Function
mA Indicates that the output current is in units of mA
μA Indicates that the output current is in units of µA
nA Indicates that the output current is in units of nA
CMP Indicates that the instrument is in voltage compliance
TABLE 3-2 Display annunciators