User guide

i
Table of Contents
Foreword................................................................................... v
Purpose and Scope
.....................................................................
v
Contents of This Manual
..........................................................
v
Applicable Hardware
...............................................................
vi
General Precautions
.................................................................
vi
Cryogen Safety
..............................................................
vi
Safety Summary
......................................................................
vii
Recommended Safety Equipment
..............................
viii
Safety Legend
.............................................................
viii
1 Introduction.............................................................................. 1
1.1
Model 187 Features
...................................................................
1
1.1.1
Compensated capacitance-based level sensing
............
1
1.1.2
Factory calibration
........................................................
1
1.1.3
Convenient display and direct keypad entry
...............
2
1.1.4
Automatic level control
.................................................
2
1.1.5
Remote computer monitoring or controlled operation
.
2
1.2
Front Panel Layout
..................................................................
3
1.3
Rear Panel Layout
.....................................................................
4
1.4
System Diagram
.......................................................................
5
1.5
Model 187 Specifications @ 25
°
C
.............................................
6
2 Installation................................................................................ 7
2.1
Unpacking the Instrument
.......................................................
7
2.2
Rack Mounting the Instrument
................................................
8
2.3
Installing the Sensor
.................................................................
8
2.4
Connecting the Model 187 to the Sensor
.................................
9
2.5
Installing the Optional Solenoid-Operated Fill Valve
..........
10
2.6
Connecting the Instrument to Power
.....................................
11
3 Operation................................................................................ 13
3.1
Operational Guidelines
...........................................................
13
3.1.1
Energizing the instrument
..........................................
13
3.1.2
Selecting the Appropriate Units
.................................
14
3.1.3
Configuring the Length Settings
................................
14
3.1.4
Configuring the HI and LO Alarms
............................
15
3.1.5
Configuring the A and B Setpoints
.............................
15
3.1.6
Selecting the Fill Mode
................................................
16
3.1.7
Configuring the Fill Timer
..........................................
16