CRYOMAGNETICS LM-500 Mode d’emploi
LM-500 Rev 1.0.doc
!"#$% &' !"$#
Web: http://www.cryomagnetics.com
WARNING!
DO NOT ATTEMPT TO OPERATE THIS EQUIPMENT BEFORE YOU
HAVE THOROUGHLY READ THIS INSTRUCTION MANUAL.
OPERATING INSTRUCTION MANUAL
FOR THE
MODEL LM-500
CRYOGENIC LIQUID
LEVEL MONITOR
CE
MANUFACTURER'S DECLARATION OF CONFORMITY
According to lSO / IEC Guide 22 and EN45014
Manufacturer's Name: Cryomagnetics, Inc.
Manufacturer's Address: 1006 Alvin Weinberg Drive
Oak Ridge, TN 37830
Declares. the product
Product Name: Liquid Cryogen Level Monitor
Model Number: LM-500
Product Options: All Options
Conforms to the following Product Specifications:
Safety: EN61010-1 (95)
EN61326-1 (97)
EMC: EN61326-1 (97) Electrical Equipment for Measurement,
Control and Lab use – EMC Requirements
EN61000-4-2 (95) Electrostatic Discharge Immunity Test
EN61000-4-3 (96) Radiated Electromagnetic Fields
EN61000-4-4 (95) Electrical Fast Transient/Burst
EN61000-4-5 (95) Amendment A-Surge Immunity Test
EN61000-4-6 (96) Amendment A-Immunity to Conducted
Disturbances
EN61000-4-11 (94) Voltage Dips, Short Interruptions and
Voltage Variations
Application of Council Directives:
The product complies with the requirements of the Low Voltage Directive
73/23/EEC as amended by 93/68/EEC and the EMC Directive 89/336/EEC as
amended by 93/68/EEC.
D.M. Coffey, President
Cryomagnetics, Inc
Oak Ridge Tennessee May 27th, 2004
TABLE OF CONTENTS
1.0 Introduction............................................................................................................................... 1
2.0 Factory Calibrations, Installed Options and Certification.......................................................... 3
3.0 Setup ........................................................................................................................................ 5
3.1 Line Voltage and Fuse .......................................................................................................... 5
3.2 Connecting Sensors.............................................................................................................. 6
3.3 LHe Sensor Calibration......................................................................................................... 8
3.4 LN2Sensor Calibration......................................................................................................... 9
3.5 Factory Calibration .............................................................................................................. 10
3.5.1 Factory Calibration of a Liquid Helium Channel........................................................... 11
3.5.2 Factory Calibration of a Liquid Nitrogen Channel ........................................................ 12
3.5.3 Factory Calibration of the Analog Output Option ......................................................... 13
4.0 Operation and Menus ............................................................................................................. 15
4.1 Liquid Helium Level Monitor Menu Options ........................................................................ 16
4.1.1 Mode............................................................................................................................ 16
4.1.2 Limits............................................................................................................................ 16
4.1.3 Fill ................................................................................................................................ 17
4.1.4 Interval ......................................................................................................................... 17
4.1.5 Units............................................................................................................................. 17
4.1.6 Boost............................................................................................................................ 17
4.1.7 Ports............................................................................................................................. 18
4.1.8 Calibrate....................................................................................................................... 18
4.2 Liquid Nitrogen Level Monitor Menu Options: ..................................................................... 19
4.2.1 Limits............................................................................................................................ 19
4.2.2 Fill ................................................................................................................................ 19
4.2.3 Units............................................................................................................................. 20
4.2.4 Ports............................................................................................................................. 20
4.2.5 Calibrate....................................................................................................................... 20
5.0 Interfacing................................................................................................................................... 21
5.1 RS-232 Computer Interface.................................................................................................... 21
5.2 IEEE-488.2 Computer Interface.......................................................................................... 22
5.3 Analog Output ..................................................................................................................... 22
5.4 Audible Alarm...................................................................................................................... 22
5.5 Automatic Refill ................................................................................................................... 23
6.0 Theory of Operation................................................................................................................ 27
6.1 Liquid Helium Level Sensing (Superconductive Filament Probes) ..................................... 27
6.2 Liquid Nitrogen Level Sensing (Capacitive Probes)............................................................ 28
6.3 LM-500 Circuit Description.................................................................................................. 28
7.0 Limited Warranty Policy.......................................................................................................... 31
Appendix A Computer Interface Command Reference ................................................................. 33
Appendix B Line Voltage Controller Module - Option 5.................................................................. 49
Cryomagnetics Model LM-500 Operating Instruction Manual 1
1.0 Introduction
The LM-500 Liquid Cryogen Level Monitor is the most advanced instrument to monitor cryogenic
liquids available today. Its versatile architecture allows configuration to virtually any cryogenic fluid.
This includes liquid helium, liquid nitrogen, LNG, and many other cryogenic fluids using an
appropriate sensing element.
With the 2-Sensor option, the instrument has two independent input channels that are factory
configurable to either the same or different liquid types. The unit is compatible with liquid helium
level sensors based upon industry standard niobium-titanium superconducting elements. Virtually all
liquid helium sensor manufacturers use this technology, so the LM-500 can be used with most
existing equipment. Flexible calibration procedures allow the use of two, three, or four wire
configured liquid helium sensors.
Capacitive sensors are used to monitor liquid nitrogen, LNG, and other cryogenic fluids. As with
liquid helium sensors, the LM-500 can monitor many manufacturer's capacitive sensors due to
advanced circuit design.
The LM-500 has user-adjustable high and low setpoints that may be used to control automated refill
cycles. With the 2-Sensor option, independent setpoints can be adjusted for each channel. This
allows simultaneous control of two liquid cryogen systems with a single LM-500. Also included is a
fully adjustable audible alarm. Most commonly set below the low setpoint, the audible alarm can be
used to alert the user to a problem with the refill cycle. A separate audible alarm setpoint is included
with the 2-Sensor option.
Unique features of the LM-500 include a sensor deicing cycle and filament burnout protection for
liquid helium systems. This insures reliable, accurate level readings even under the most adverse
cryogenic conditions. Computer control via RS-232 is available in the standard configuration.
Remote control via the latest IEEE-488.2 command set is available as an option. LabVIEW® virtual
instrument drivers are available to allow computer control via a familiar, intuitive interface. A wide
variety of other options are also available that allow the instrument to be upgraded and tailored to
your particular requirements.
Cryomagnetics Model LM-500 Operating Instruction Manual 2
This Page Intentionally Left Blank
Cryomagnetics Model LM-500 Operating Instruction Manual 3
2.0 Factory Calibrations, Installed Options and Certification
LM-500 Serial Number:
Input Voltage: 100 VAC: 115 VAC: 230 VAC:
Input Channel 1:
Type: LHe LN2 Other:
Calibration: Sensor Manufacturer / Serial No:
Sensor Length:
Characteristic Resistance/Voltage:
Lead Resistance:
Control Output: TTL: Open Collector: ________ Other: __________
Input Channel 2 (Option 3): Not Installed:
Type: LHe LN2 Other:
Calibration: Sensor Manufacturer / Serial No:
Sensor Length:
Characteristic Resistance/Voltage:
Lead Resistance:
Control Output: TTL: Open Collector: _______ Other:
Analog Output (Option 1): Not Installed:
Type: 0-1 Volt: 4-20mA:
Computer Interface Installed: RS-232: X IEEE-488.2 (Option 2):
Notes:
Certified:
Date:
Cryomagnetics Model LM-500 Operating Instruction Manual 4
This Page Intentionally Left Blank
Autres manuels pour LM-500
1
Table des matières
