Hall Probe Calibration System

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Hall Probe Calibration System Using LabVIEW
Joseph Z. Xu August 11, 2003
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APS INSERTION DEVICES
The magnetic field spatial distribution profiles
of the APS Insertion Devices (ID) are
characterized with Hall Probe Magnetic
Measurement System
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Hall Effect and Hall Probe
Hall Effect
Hall Probe

• Hall Probes are used to characterize the magnetic
  field spatial distribution profiles of the APS
  Insertion Devices (ID)
• The Hall Probe Calibration System is designed to
  calibrate the Hall Probes

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Hall Probe Calibration System
The Hall Probe Calibration System consists of
Dry Cooper
A Magnetic Power Supply (MPS-853)
An Electrical Magnet
GPIB
An NMR Teslameter (PT-2025)
A Reference Teslameter (DTM-141)
RS-232
A Motorized Probe Stage (SmartMotor)
A Multimeter (HP-3458A)
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NMR Theory of Operation
G µ/hI
?E µB/I
f ?E/h GB
µ nuclear magnetic moment f resonance frequency
B static magnetic field I spin quantum number
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Operation Procedure
Electric Magnet Top View
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What is LabVIEW?

• A graphical programming language
• Compiled graphical development environment
• Similar to flowcharting

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Virtual Instrument

• Each program is called a Virtual Instrument (VI)
• Each VI has a Front Panel and a Block Diagram

Front Panel User Interface (MEDM)
Block Diagram Source Code (IOC Application)
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Front Panel User Interface

• Graphical user interface
• Pre-built user interface objects

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Block Diagram Source Code

• Intuitive flowchart-like code
• Hundreds of pre-built measurement subVIs
• Self-documenting

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Debugging
Step in, single step, step out
Highlight execution
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Application Builder
Compiler Creates Application.exe
and Application.ini files
Installer Creates data.cab, install.msi InstMsi.ex
e, setup.ini, InstMsiW.exe, and setup.exe files
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Hall Probe Calibration System Software
Main Panel
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Hall Probe Calibration System Software
Reference Teslameter (DTM-141)
DTM-141 Reference Digital Teslameter Panel
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Hall Probe Calibration System Software
NMR Teslameter (PT-2025)
PT-2025 NMR High Precision Teslameter Panel
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Hall Probe Calibration System Software
Magnetic Power Supply (MPS-853)
MPS-853 Magnetic Power Supply Panel
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Hall Probe Calibration System Software
MPS-853 Magnetic Power Supply Panel Interlock
Pull Down Menu
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Hall Probe Calibration System Software
Multimeter (HP-3458A)
HP-3458A Panel
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Hall Probe Calibration System Software
Motorized Probe Stage (SmartMotor)
Motorized NMR Probe Stage Panel
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Hall Probe Calibration System Software
Plot Panel
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Hall Probe Calibration System Contents
System Hardware

1. Danfysik System 8000 MPS-853 Precision Magnet
   Power Supply System
2. Electric Magnet
3. Metrolab PT-2025 High Precision NMR Teslameter
   System
4. Motorized NMR Probe Support Stage System Powered
   by Animatics SmartMotor Servo Motors
5. Group 3 DTM-141 Digital Teslameter System
6. HP 3458A Multimeter System
7. PC with a GPIB PCI card, a RS-232 port, 600 MHz
   or higher CPU, 128 MB or more RAM, and 130 MB or
   more free HD.

System Software and Documents

1. Windows XP/2K/NT/98 OS.
2. PC based software package with installer on a CD
3. Users Guide
4. Operation Method of Procedure

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Next Project Integral (Stretch Coil) Measurement
System Upgrade
Field integral (along the z direction) Theory of
Operation
Vertical Component
Horizontal Component
Y
1
4
X
Y
2
3
1
4
2
3
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Key System Requirements

• Motion Control SmartMotor via RS-232
• 2x4 axis x(0-400mm), y(0-400mm), z(0-6000mm),
  w(0-360)
• Motion Readout Linear (x, y, and z) and Rotary
  (w) Encoders
• Linear encoder resolutions 25 µm absolute
  position
• Rotary encoder resolutions 0.1deg absolute angle
  position
• Linear stage speed up to 50 mm/s at z direction
• Rotary stage speed up to 1 revolution per second
• DAQ Coil EM Voltage Measurement
• Resolution 16 bit (5 digits)
• Sampling rate 1.5 kS/s
• Synchronization Absolute Angle Position vs. Coil
  Voltage Measurement w/ at 1.5 kS/s
• Triggering must be done in referencing of
  absolute positions.
• Digital I/O Noise Control 10-7

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Current System Architecture
System A (on the 6 meter bench)
Stepping Motor Drivers Stepping Motor Power
Supplies
To the Stepping Motors
VME
VME44 w-Encoder Board
VMEX xyz-Encoder Board
PCI NIVXI
From the encoders
PCI GPIB
Magnetic Flux Integrator
From the Coil
Amplifier

• Current Issues
• Flux start point and finish points (positions)
  are not well defined.
• Only 4 data points are measured and data analysis
  is not feasible.
• System is Windows 3.1 based and software is not
  upgradeable.

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Current System Architecture
System B (on the 3 meter bench)
To the SmartMotors
From the Coil
RS-485
PowerDAQ 16 bit PCI ADC Card
RS-232
RS-232 to RS-485 Converter
Amplifier

• Current Issues
• Positioning and measurements are synchronized
  by PC CPU time using software. ( 3 ms?)
• Start and Finish positions/times are not well
  defined.
• System is RedHat Linux based and hard to maintain.

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Proposed System Architecture
From x, y, z, and w encoders
TCP/IP
PXI
FPGA I/O w/ built in 16 bit ADC
From the Encoders
From the Coils
RS-232
To the SmartMotors

• Key Features
• Integrated real time encoder readout, triggering,
  and Coil voltage measurement.
• TCP/IP Interface, securely access the system
  remotely, anywhere, anytime.
• Commercial off-the-shelf components.
• Same hardware can be used for both 6 meter bench
  and 3 meter bench Hall Probe Measurement Systems.

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Why PXI?

• PXI PCI eXtensions for Instrumentation
• A specification designed explicitly for
  industrial test and control applications.
• Industry open standardized PCI backplane at 132
  MB/s or 1 Gbps (32 bits_at_33MHz) plus integrated
  timing and triggering.
• Well supported by all major operating systems.
• Large selection of instruments and modules.
• Low cost and ease of use.

See www.pxisa.org for detailed specifications
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Conclusion
For isolated control and data acquisition
systems, PC based and/or PXI based platform with
LabVIEW, Visual Basic, or Visual C development
tools shall be adequate.
Hall Probe Calibration System Demo Diagram
TCP/IP
802.11
RS-232
SmartMotor NMR Probes
GPIB
Magnetic Power Supply (MPS-853)
Reference Teslameter (DTM-141)
NMR Teslameter (PT-2025)
Digital Multimeter (HP-3458A)
Electric Magnet