American Magnetics 185 & 186 Liquid Level Instruments (CE-Marked) - Manual (Page 5)

Rev. 3 v
Table of Contents
1 Introduction .............................................................................. 1
1.1 Model 185/186 Features............................................................ 1
1.2 Model 185 Front Panel.............................................................. 3
1.3 Model 185 Rear Panel ............................................................... 4
1.4 Model 186 Front Panel Layout ................................................ 5
1.5 Model 186 Rear Panel Layout .................................................. 6
1.6 Model 185/186 Specifications @ 25 °C ...................................... 8
2 Installation .............................................................................. 11
2.1 Unpacking the Instrument ..................................................... 11
2.2 Rack Mounting the Instrument.............................................. 12
2.3 Installing the Sensor in the Cryo-vessel ................................ 12
2.4 Connecting the Oscillator Cable to the AMI Sensor ............. 13
2.5 Connecting the Instrument to the Oscillator......................... 13
2.6 Installing an Optional Solenoid-operated Fill Valve............. 14
2.7 Connecting the Instrument to Power..................................... 15
3 Calibration .............................................................................. 17
3.1 Relationship between Calibration and Sensor Length ......... 17
3.2 Variations in the Dielectric with Changing Density ............. 17
3.3 Calibration Methods for Model 185/186 Instruments ........... 19
3.3.1 Open dewar calibration ............................................... 21
3.3.2 Closed dewar calibration............................................. 21
3.3.3 Approximate calibration ............................................. 25
4 Operation ................................................................................ 29
4.1 Normal Operations.................................................................. 29
4.1.1 Energize the instrument ............................................. 29
4.1.2 Configure the active length setting ............................ 29
4.1.3 Configure the HI SETPOINT and the
LO SETPOINT............................................................. 30
4.1.4 Configure the A SETPOINT and the B SETPOINT.. 31
4.1.5 Select the operational mode of the controller
output receptacle ......................................................... 32
4.1.6 Configure the INTERVAL setting (fill timer)
if desired....................................................................... 32
4.1.7 Select the appropriate units display option ............... 33
4.1.8 Connect the optional analog output signal ................ 33
4.2 Sensor Contamination ............................................................ 34