American Magnetics 135 & 136 Liquid Helium Level Instruments (CE-Marked) - Manual (Page 28)

16 Rev. 3
Operation
Normal Operational Mode
Note
If the displayed level reading is below the LO SETPOINT level or
exceeds the HI SETPOINT, an audible alarm will sound. To silence
the alarm, rotate the control mode rotary switch on the front panel to
the SILENCE position.
3.2.2 Configure the active length setting
Note
The Model 135/136 instrument is calibrated at the factory. No
further calibration is required, however the length setting of the
instrument must be matched with the active length of the sensor that
is attached for proper operation.
Initially the instrument must be adjusted for the active length of the
sensor. Place the units mode toggle switch in either the INCH or CM
position. Place the control mode rotary switch on the front panel to the
LENGTH position. To view the present length setting, push and release
the RAISE/LOWER toggle switch either up or down. The display will
momentarily show the present length setting. To change the length
setting, use the RAISE/LOWER toggle switch to move the setting up or
down by continuously holding it in the up or down position. The display
will move slowly at first and then faster. Once near the desired value,
simply release the switch momentarily and then resume changing the
setpoint at the slower speed.
The new active sensor length is automatically permanently stored in
memory. Check the value by momentarily placing the toggle switch in
either position from the center position.
Note
The LENGTH adjustment can only be performed in the INCH or
CM units modes. The LENGTH adjustment is inactive if the units
are set for %.
3.2.3 Configure the HI SETPOINT and the LO SETPOINT
To adjust the HI and LO setpoints, place the control mode rotary switch in
the HI SETPOINT position or the LO SETPOINT position, respectively.
Use the RAISE/LOWER toggle switch to adjust the respective setpoint in
the same manner as described for the LENGTH adjustment in paragraph
3.2.2. The setpoints may be located anywhere between 0% to 100% of the
active sensor length. The HI and LO setpoint adjustments are compatible
with all three units modes.