Helium Level Meter

 

A. Check (and adjust) sensor length

  1. Set right toggle switch to ´INCH´
  2. Set left knob to ´LENGTH´
  3. Push for 1 sec left toggle switch to either ´RAISE´ or ´LOWER´ ==> DISPLAY shows present LENGTH in INCH
  4. For change of sensor length repeat step 1c and adjust new length by holding the toggle switch up or down. OS - X ==> 16 inch sensor length; O - X ==> 16 inch " "; OM - X ==> 30 inch " "LHe-Vessel ==> 18 inch " "

B. Check (and adjust) measuring intervall times

  1. Set middle toggle switch to ´CONTIN´ for a continous reading (during LHe-transfer or for immediate reading, only; for longer times the continous heat input results in an increased LHe boil-off)
  2. Set middle toggle switch to ´SAMPLE´
  3. Set left knob to ´INTERVAL´
  4. Push for 1 sec left toggle switch to either ´RAISE´ or ´LOWER´ ==> DISPLAY shows present SAMPLE INTERVAL TIME in MINUTES
  5.  For change of sample intervall time repeat step 2d by holding the toggle switch up or down and adjust new sample intervall time.

C. Operation settings for LHe-level monitor

  1. Right toggle switch to ´CM´
  2. Middle toggle switch to ´SAMPLE´
  3. Sample intervall 5 minutes
  4. Sensor length 16 inch 40.6 cm