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Lake Shore Model 421 Gaussmeter User’s Manual
3-12
Operation
3.13 LOCKING AND UNLOCKING THE KEYPAD
The Model 421 front panel keypad may be locked, preventing inadvertent changes to the settings. To
lock the keypad, press and hold the
Max Hold
key (
≈
10 seconds) until the following display is seen.
Lock Keypad
The keypad is now locked. Any attempt to change settings causes the
*LOCKED*
message to briefly be
displayed on the top line of the display. The only exception is the user may still use the
Alarm
key to
turn off an alarm even though the keypad is locked.
To unlock the keypad, again press and hold the
Max Hold
key until the following display is seen.
Unlock Keypad
The keypad is now unlocked and the display will revert to the normal display.
3.14 DISPLAY BRIGHTNESS
The overall brightness of the front panel vacuum florescent display is user controllable. Press and hold
the
Relative
key until you see the following display.
Select With °®
Brightness
Use the
s
or
t
keys until you see the desired brightness. Press the
Enter
key to accept the new
setting. There are four levels of brightness. The brightness can also be set using the BRIGT command
via the Serial Interface. Using the highest brightness setting may shorten the life of the display.
3.15 FACTORY DEFAULT SETTINGS
Press and hold the
Max Reset
key for
≈
20 seconds. This causes the following functions to return to
their factory default settings. The defaults are listed as follows:
AC/DC........................... DC
Alarm ............................ Off
Auto Range................... Off
Baud ............................. 300
Brightness..................... 4
Fast Data Mode ............ Off
Filter.............................. Off
Gauss/Tesla.................. Gauss
Keypad.......................... Not Locked
Max Hold....................... Off
Range ........................... Highest Range For Probe
Relative......................... Off
Other gaussmeter calibration information and probe data are not affected by this reset. Zero the probe
after this operation.