Metrol TFM1186 User manual

Pantone 286 Pantone 032
Magnetic precision has a name
Three-axis Magnetometers
THM1176 and TFM1186
User's Manual
Version 1.3
(Revision 1.2)
April 2014

THM1176/TFM1186 User’s Manual v 1.3 r 1.2 – 04/14 Copyright © 2014 Metrolab Technology SA
www.metrolab.com
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REVISION HISTORY
v. 1.0 r. 1.0
May 2008
First release
v. 1.0 r. 1.1
May 2008
Various fixes
v. 1.1 r. 1.0
July 2008
Various fixes
v. 1.2 r. 1.0
December 2009
Updates for version 3.x of software
Updates for version 2.x of firmware
Updates for THM1176-LF
Various fixes
v. 1.2 r. 1.1
February 2010
Add notice concerning WEEE Directive
v. 1.2 r. 1.2
July 2010
Restore formatting of -HF dimensions
v. 1.3 r. 1.0
January 2012
Update for software release 4.0 and firmware
release 3.0
Update links for external documentation
Add documentation for THM1176-HFC
v. 1.3 r. 1.1
April 2012
Correct installation procedure
v. 1.3 r. 1.2
April 2014
Add documentation for THM1176-MF, TFM1186
Adapt documentation for SoMo™ 655
Remove references to electronic newsletter
Update links to USB documentation
Update for LabVIEW Mobile Module end-of-life
Miscellaneous clean-ups

THM1176/TFM1186 User’s Manual v 1.3 r 1.2 – 04/14 Copyright © 2014 Metrolab Technology SA
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CONTENTS
GETTING STARTED .................................................................................................1!
1-!Introduction........................................................................................................1!
GETTING STARTED .................................................................................................3!
2-!Quick Start Guide ..............................................................................................3!
2-1!Using the THM1176/TFM1186 with a desktop computer......................................................................... 3!
2-1-1!PC: Software Installation ............................................................................................................... 3!
2-1-2!Mac: Software Installation ............................................................................................................. 3!
2-1-3!PC or Mac: Measurement.............................................................................................................. 4!
2-2!Using the THM1176/TFM1186 with the Handheld................................................................................... 4!
2-2-1!Handheld: Assembly...................................................................................................................... 4!
2-2-2!Handheld: Measurement ............................................................................................................... 5!
2-3!Software Development............................................................................................................................. 5!
2-4!Precautions.............................................................................................................................................. 6!
2-5!Notes........................................................................................................................................................ 9!
USING THE THM1176/TFM1186 ............................................................................11!
3-!Overview...........................................................................................................11!
3-1!Measurement ......................................................................................................................................... 11!
3-2!Interface ................................................................................................................................................. 13!
3-3!Probe Mechanical Design...................................................................................................................... 14!
3-4!Desktop Kit............................................................................................................................................. 15!
3-5!Handheld Kit .......................................................................................................................................... 16!
3-6!Calibration, Maintenance, Repair and Warrenty.................................................................................... 17!
USING THE THM1176/TFM1186 ............................................................................19!
4-!Software User Interface...................................................................................19!
4-1!Numeric Display..................................................................................................................................... 19!
4-2!Plot Display ............................................................................................................................................ 21!
4-3!File Display ............................................................................................................................................ 23!
4-4!Setup Display......................................................................................................................................... 25!
4-5!Measure Setup Dialog ........................................................................................................................... 26!
4-6!Alarm Setup Dialog................................................................................................................................ 28!
4-7!Bus Trigger Dialog ................................................................................................................................. 29!
PROGRAMMING THE THM1176/TFM1186............................................................30!
5-!Application Programming Interface...............................................................30!
5-1!General .................................................................................................................................................. 30!
5-2!AVERage ............................................................................................................................................... 31!
5-3!CALibration ............................................................................................................................................ 32!
5-4!Close...................................................................................................................................................... 32!
5-5!Enumerate ............................................................................................................................................. 33!
5-6!Expand Data .......................................................................................................................................... 33!

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5-7!FORMat ................................................................................................................................................. 34!
5-8!Initialize .................................................................................................................................................. 35!
5-9!MEASure_FETCh_READ ...................................................................................................................... 35!
5-10!MMEMory............................................................................................................................................... 37!
5-1!Read STB w Timeout............................................................................................................................. 37!
5-1!READ ..................................................................................................................................................... 37!
5-2!Reset...................................................................................................................................................... 38!
5-3!Revision Query ...................................................................................................................................... 38!
5-4!Self-Test................................................................................................................................................. 39!
5-5!SENSe ................................................................................................................................................... 39!
5-6!STATus .................................................................................................................................................. 40!
5-7!Straighten............................................................................................................................................... 41!
5-8!TRIGger ................................................................................................................................................. 42!
5-9!UNIT....................................................................................................................................................... 43!
5-10!Write and Read...................................................................................................................................... 43!
PROGRAMMING THE THM1176/TFM1186............................................................44!
6-!USB Interface ...................................................................................................44!
6-1!General .................................................................................................................................................. 44!
6-2!SCPI Instrument Model.......................................................................................................................... 45!
6-3!IEEE 488.2 / SCPI status registers ........................................................................................................ 48!
6-4!USBTMC-USB488 Controls................................................................................................................... 51!
6-5!IEEE 488.2 Common Commands.......................................................................................................... 52!
6-6!SCPI Commands ................................................................................................................................... 52!
6-7!Programming Hints ................................................................................................................................ 65!
REFERENCE ...........................................................................................................68!
7-!Technical Specifications.................................................................................68!
7-1!Measurement ......................................................................................................................................... 68!
7-2!Interface ................................................................................................................................................. 69!
7-3!Operating conditions .............................................................................................................................. 69!
7-4!Mechanical – THM1176-MF/HF............................................................................................................. 70!
7-5!Mechanical – THM1176-HFC ................................................................................................................ 71!
7-6!Mechanical – THM1176-LF.................................................................................................................... 72!
7-7!Mechanical – TFM1186 ......................................................................................................................... 72!
7-8!Desktop kit ............................................................................................................................................. 73!
7-9!Handheld kit........................................................................................................................................... 73!
7-10!Warranty, Calibration, Certification and Maintenance............................................................................ 74!
REFERENCE ...........................................................................................................75!
8-!THM1176-MF/HF/HFC Sensor Details ............................................................75!
REFERENCE ...........................................................................................................78!
9-!Error Codes ......................................................................................................78!

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9-1!0: No Error ............................................................................................................................................. 78!
9-2!-100: Command Errors .......................................................................................................................... 78!
9-2-1!-102: Syntax error........................................................................................................................ 78!
9-2-2!-104: Data type error ................................................................................................................... 78!
9-2-3!-115: Unexpected number of parameters.................................................................................... 78!
9-2-4!-123: Exponent too large ............................................................................................................. 78!
9-2-5!-151: Invalid string data ............................................................................................................... 78!
9-2-6!-171: Invalid expression............................................................................................................... 79!
9-3!-200: Execution Errors ........................................................................................................................... 79!
9-3-1!-221: Settings conflict .................................................................................................................. 79!
9-3-2!-222: Data out of range................................................................................................................ 79!
9-3-3!-225: Out of memory.................................................................................................................... 80!
9-4!-400: Query Errors ................................................................................................................................. 80!
9-4-1!-400: Query error ......................................................................................................................... 80!
9-4-2!-410: Query INTERRUPTED ....................................................................................................... 80!
9-4-3!-420: Query UNTERMINATED .................................................................................................... 80!
9-4-4!-440: Query UNTERMINATED after indefinite response............................................................. 80!
9-5!100: Instrument-Dependent Command Errors....................................................................................... 80!
9-5-1!101: Invalid value in list ............................................................................................................... 80!
9-5-2!103: Wrong units for parameter................................................................................................... 80!
9-6!200: Instrument-Dependent Execution Errors........................................................................................ 80!
9-6-1!200: Software Error ..................................................................................................................... 80!
9-6-2!204: Data buffer was overrun ...................................................................................................... 81!
9-6-3!205: Measurements were over-range.......................................................................................... 81!
9-6-4!206: Timer was overrun............................................................................................................... 81!
9-6-5!207: Bad data compression......................................................................................................... 81!

THM1176/TFM1186 User’s Manual v 1.3 r 1.2 – 04/14 Copyright © 2014 Metrolab Technology SA
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1
GETTING STARTED
1-
Introduction
Metrolab’s Three-axis Magnetometers are used to measure magnetic field
strength. Their unique, extraordinarily compact design allows them to be used as
a portable instrument or directly connected to a PC. Simultaneous measurement
of all three components of the magnetic field provides the total field no matter the
orientation of the probe, which greatly facilitates many measurement tasks such
as field mapping.
This manual covers the entire THM1176 family, including the following models:
•THM1176-MF (“Three-axis Hall Magnetometer – Medium Field”),
•THM1176-HF (“Three-axis Hall Magnetometer – High Field”),
•THM1176-HFC (“Three-axis Hall Magnetometer – High Field Compact”),
•THM1176-LF (“Three-axis Hall Magnetometer – Low Field”), and
•TFM1186 (“Three-axis Fluxgate Magnetometer”).
For an overview of each of these instrument’s capabilities, please see Chapter 3-
Overview, Chapter 7-Technical Specifications and Chapter 8-THM1176-
MF/HF/HFC Sensor .
The THM1176 family instruments resemble other standard USB devices; it and its
software are easy to install and easy to use. Nonetheless, please take a moment
to browse through Chapter 2-Quick Start Guide and Chapter 4-Software User
Interface. Pay particular attention to the cautionary notes in Chapter 2-Quick Start
Guide.
It is easy to develop custom software for the THM1176 family, especially in
LabVIEW. Please see Chapter 5-Application Programming Interface, Chapter 6-
USB Interface, and Chapter 9-Error Codes.
Finally, keep your instrument accurate and up to date by having it recalibrated at
regular intervals. The recommended calibration interval is 18 months. You can
benefit from a discounted price for the calibration if you return your instrument to
Metrolab at a time that corresponds to our batch calibrations; please see Section
7-10 for details.

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You can also download the latest firmware, software and manual, free of charge.
We post all updates on our website. Section 3-6 provides some additional details.
We hope the THM1176/TFM1186 will help you perform your magnetic field
measurements easily and accurately. If you have problems and your reseller
cannot help you further, the Metrolab team is ready to help. Even if you don’t have
problems, we are always interested in knowing more about how our instruments
are used. Feel free to contact us at any time at [email protected].

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GETTING STARTED
2-
Quick Start Guide
2-1 USING THE THM1176/TFM1186 WITH A DESKTOP COMPUTER
2-1-1 PC: Software Installation
•Insert the installation CD.
•Install the National Instruments LabVIEW Runtime Engine 2010 SP1 by
double-clicking on
\PC\LVRTE2010sp1std.exe.
•Install the National Instruments VISA Runtime Library by double-clicking on
\PC\visa511runtime.exe.
•Install the THM1176 software by double-clicking on
\PC\THM1176\setup.exe.
2-1-2 Mac: Software Installation
•Insert the installation CD and open the Mac directory.
•Install the National Instruments LabVIEW Runtime Engine 2010 SP1 by
double-clicking on
/Mac/mac LabVIEW 2010sp1 Run-Time Engine.dmg
and then double-clicking on the installation package
LabVIEW 2010 Runtime Engine.mpkg.
•Install the VISA Runtime Library by double-clicking on
/Mac/NI-VISA-Runtime-5.1.1_Beta.dmg
and then double-clicking on the installation package
nivisaruntimei.mpkg.
•Install the THM1176 application by decompressing
/Mac/THM1176.zip
and copying the application to your Applications folder.

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NOTICE
⇒If needed – for example, if you install a new operating system on your
computer – you can download and install more recent versions of the VISA
Runtime Library from the National Instruments website (http://www.ni.com).
⇒You may already have NI-VISA installed, for example if you use LabVIEW.
2-1-3 PC or Mac: Measurement
•Start the THM1176 measurement software.
In Windows, if you used the standard installation options, a THM1176 link
is located in the Metrolab\THM1176 program group of the All Programs
menu.
•Plug in the THM1176/TFM1186.
The measurement software should automatically recognize the instrument
and start measuring.
In Windows XP, the New Hardware Wizard will run the first time you plug in
the instrument, requiring access to an Administrator account. Choose not
to connect to Windows Update and to install the software automatically.
Subsequently, chimes will indicate when the instrument has started up.
•Place the probe into the magnet. On the THM1176-MF and THM1176-HF,
you can remove the probe cap to access narrow gaps – see Chapter 3-
Overview. See Chapter 4-Software User Interface for details on using the
software.
•(Does not apply to TFM1186 – see Section 2-4!) Check the offset before
each series of measurements by placing the probe in the Zero Gauss
Chamber. If the offset is higher than desired, leave the probe in the Zero
Gauss Chamber and perform the User Offset Correction procedure using
the Offset / ZERO button on the Setup page.
2-2 USING THE THM1176/TFM1186 WITH THE HANDHELD
2-2-1 Handheld: Assembly
•Install the battery in the PDA and charge it. You can charge the battery in
three ways:

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oLift the rubber cover covering the DC-in connector on the bottom left
side of the PDA and plug in the AC adaptor.
oPlug the short USB-Host adaptor cable into the USB synchronization
cable connector on the bottom of the PDA, and plug the AC adaptor
into the power connector on the USB-Host adaptor cable.
oPlug the 1.2 m long USB-Device adaptor cable that plugs into the
USB synchronization cable connector on the bottom of the PDA, and
plug the other end of the adaptor cable into the USB port of a PC.
•Turn on the PDA by: (1) sliding the Hold switch on the left side of the PDA
to the unlocked position (up); and (2) pressing the Power button on the top
right-hand corner of the front of the PDA.
•If you have not done so yet, plug the short USB-Host adaptor cable into the
USB synchronization cable connector on the bottom of the PDA.
•Plug the THM1176/TFM1186 into the USB-Host adaptor cable.
2-2-2 Handheld: Measurement
•Press the big button on the right side of the PDA to start the measurement
software. Alternatively, you can use the THM1176 icon in the Programs
folder of the Start menu.
•Press the big button on the left side of the PDA to bring up the virtual
keyboard. Press it again to hide the keyboard. The software should show
and hide the keyboard automatically when appropriate.
•Be sure to stop the measurement software using the Stop button before
turning off the PDA or unplugging the THM1176/TFM1186 – see the note
below.
•Manipulate the probe and check the offset as described in Section 2-1-3.
2-3 SOFTWARE DEVELOPMENT
•Insert the installation CD.
•Copy the Source folder to your hard drive. The API subfolder contains the
Application Programming Interface – see 5-Application Programming

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Interface. The UIF folder contains the source code of the THM1176
measurement software.
•Modify the THM1176 measurement software, or write a measurement
system from scratch, using the LabVIEW development system. Developing
software for the handheld version requires the optional LabVIEW Mobile
Module (LabVIEW 2011SP1 or earlier).
2-4 PRECAUTIONS
CAUTION
⇒High magnetic field gradients – as found, for example, around an MRI or NMR
spectroscopy magnet – will subject the USB connector and the PDA to strong
forces. To prevent injury from flying objects or whiplashing cables, be sure to
hold these components securely when you are around a strong magnet.
NOTICE
⇒Do not bend the probe cable sharply. This is a special cable with individually
shielded signal wires, in order to minimize induction artifacts. Sharp bends
break the shielding.
⇒This product conforms to the WEEE Directive of the European
Union (2002/96/EC) and belongs to Category 9 (Monitoring and
Control Instruments). For proper environment friendly disposal,
you can return the instrument free of charge to us or our local
distributor.
SPECIAL NOTICE FOR THE HANDHELD
⇒For details about using the PDA, please refer to the “SoMo™ 650/655 Quick
Start Guide.” This includes important safety instructions.
⇒On the SoMo™ 650, take care to squeeze the two release buttons on the side
of the connector when removing the adaptor cables from the bottom of the
PDA. Else you will destroy the cable locking mechanism, and in the future the
connector can accidentally slip loose.
!

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SPECIAL NOTICE FOR THE HANDHELD
⇒Due to a bug in the VISA library, the PDA version of the THM1176 software
cannot handle disconnecting the THM1176 while it is measuring. This has two
implications:
oYou must stop the measurement software before unplugging the
THM1176/TFM1186.
oYou must also stop the measurement software before placing the PDA
in sleep mode. The PDA can be placed in sleep mode manually by
pressing the Power button. The PDA can also be placed in sleep mode
automatically by the power saver – see
Start!Settings!System!Power!Advanced. By default, Metrolab
disables automatic sleep.
Failure to follow these instructions will hang the measurement software in such
a way that it cannot be stopped. The only way to reactivate it is to reset the
PDA by using the stylus to press the Soft reset button on the bottom of the
PDA.
⇒When exposed to a strong magnetic field, the touch screen of the PDA will
cease to function. The power of the PDA must be cycled to restore full
operation.
SPECIAL NOTICE FOR THE THM1176-HF and THM1176-HFC
⇒Remember that the THM1176-HF is only calibrated to 14.1 T (formerly 3 T),
and the THM1176-HFC only to 1.5 T. Consequently, the 20 T range on these
instruments is only calibrated up to these limits. You should try to use the
lower ranges whenever possible; the best is to leave the instrument in auto-
ranging mode (the default).

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SPECIAL NOTICE FOR THE THM1176-HFC
⇒The probe is very fragile. Be extremely careful when handling; even the weight
of the instrument cable is sufficient to damage the probe. Damage to either the
sensor IC or PCB will destroy the sensor. We strongly suggest storing the
probe in its protective case when not in use.
⇒The probe cable is also fragile. Avoid pulling on it or bending it sharply,
especially near the junction of the instrument and probe cables. Do not let the
protective case hang by the sensor cable.
⇒The sensor is sensitive to Electrostatic Discharge (ESD). Be sure to ground
yourself and follow proper procedure when handling the sensor.
⇒The probe is supplied with two ceramic plates that can be glued to the top and
bottom of the sensor PCB. The benefits are that the sensor PCB is protected
and rendered rigid, and that the ceramic provides a flat reference surface. The
disadvantages are that the sensor becomes thicker, and that it cannot be
recalibrated. Because of this trade-off, Metrolab have decided to leave it to the
customer to decide whether or not they want to use the ceramic plates.
⇒Without the ceramic plates, the sensor PCB can be bent anywhere in the front
15 mm of the sensor PCB. The minimum bend radius is 3-4 mm. Note that
during calibration, Metrolab use a bend radius of 20 mm, using the entire
length of the sensor PCB. The gold conductive traces should be on the inside
of the bend.
SPECIAL NOTICE FOR THE TFM1186

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SPECIAL NOTICE FOR THE TFM1186
⇒Do not use the zero-offset correction feature with the TFM1186. In fact, the
fluxgate sensor is so sensitive that most zero-gauss chambers are completely
inadequate, and the zero-offset procedure will introduce a large offset error. If
the zero-offset procedure is accidentally executed, the factory offset can be
restored using the “:CAL:ZERO” command (see Section 6-6).
2-5 NOTES
•The orientation of the axes relative to a THM1176 probe is as follows:
Relative to the THM1176-MF and -HF sensors:
Similarly for the THM1176-HFC sensor:
For the TFM1186, the axis orientations are printed on the sensor.
•A recording file is an ASCII file organized into columns, delimited by tabs:
oBlock: sequential number for block of measurements.
oB: total field.
oBx, By, Bz: X-, Y- and Z-components of field, respectively.
X
Z
Y
Z
X
Z

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oUnits: as selected when the data was recorded.
oTemperature: the units are arbitrary; i.e. not calibrated in degrees.
oTimestamp: date and time, with 1 ms resolution.
oSerial No.: instrument serial number.
oComment: as entered on the File panel.
Every line is terminated by an end-of-line marker.
•Some PDA USB-Host adaptor cables may not have a power connector.
Plug the AC adaptor into the DC-in connector on the PDA instead.
•If you plug the THM1176/TFM1186 into the PDA before the PDA completes
its initial boot procedure, you will see an “Unidentified USB Device” dialog.
Simply unplug the THM1176/TFM1186, cancel the dialog, and plug the
THM1176/TFM1186 back in when you see the PDA’s Today screen.
•If you are using a Windows PC, the Windows Mobile Device Center or
Microsoft ActiveSync software will simplify file transfers between the PDA
and your PC. Please refer to the SoMo Quick Start Guide.
•The \PDA\Reinstall directory on the THM1176 installation CD contains the
files and instructions required to reinstall the PDA software.

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11
USING THE THM1176/TFM1186
3-
Overview
This chapter provides a quick overview of what you can do with the THM1176
family of instruments. Additional details are provided in subsequent chapters.
3-1 MEASUREMENT
•Three axes:
Simultaneous measurement of all three axes of the magnetic field provides
the total field, no matter the orientation of the probe.
•Field sensitive volume:
On the THM1176-MF, -HF and -HFC, a microscopic Hall sensor volume
provides localization to a fraction of a mm, and a self-consistent
measurement of the three axes even in highly inhomogeneous fields. The
active field volume of the THM1176-LF and TFM1186 is much larger, on
the order of several mm, but this is usually sufficient for weak fields.
•Range, accuracy and resolution:
Consult these key specifications and choose the probe most appropriate
for your application:
oTHM1176-MF: general-purpose up to 3 T;
oTHM1176-HF: superconducting magnets to 14 T;
oTHM1176-HFC: sub-millimeter gaps; and
oTHM1176-LF: millitesla fringe fields;
oTFM1186: nanotesla-range perturbations.
•Bandwidth of DC to 1 kHz:
The 1 kHz bandwidth allows measuring AC fields generated, for example,
by transformers and motors.
•Trigger modes:
Three trigger modes allow the acquisition procedure to be fine-tuned for the
measurement.

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oImmediate trigger mode:
Immediate trigger mode – the default – starts an acquisition
sequence immediately upon receiving the measurement command.
oTimed trigger mode:
Timed trigger mode is suitable for measuring rapidly varying fields.
The maximum sample rate – writing data into the acquisition buffer –
is approximately 5 kSa/s, where one sample is a triplet (Bx, By, Bz).
With a simultaneous readout via USB, the maximum sample rate is
approximately 2.3 kSa/s.
oBus triggered mode:
The USB bus trigger command can be used to synchronize the
acquisition with external events. The instrument allows up to about
400 bus triggers per second.
•Acquisition buffer:
The THM1176/TFM1186 contains a local memory capable of holding 4096
samples, allowing data to be acquired more quickly than it can be read out
by the USB interface.
•Averaging:
Averaging can reduce measurement noise. The degree of averaging is
controllable, since long integration periods might be beneficial for static
fields, but counterproductive for time-varying fields. The THM1176 family
uses a simple arithmetic mean, and performs N measurements of each
axis in succession; for example, for N=3, the measurement sequence
would be:
Bx, Bx, Bx, By, By, By, Bz, Bz, Bz, T
where T is temperature. When performing multiple measurements into the
acquisition buffer, the temperature is also averaged, in order to take into
account temperature drift during a lengthy measurement sequence.
•User offset correction (not for TFM1186 – see Section 2-4!):
To guarantee the specified accuracy, the measurement offset should be
checked before each measurement sequence, using the zero-gauss
chamber supplied. If needed, the offset correction procedure will measure
and correct this offset. The correction value is written to flash memory so

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that the same correction will be applied the next time the instrument is
powered up.
•Readout options:
The three field components are always acquired, but the readout can be
limited to any selected components. The readout can include a single
measurement or an entire array of measurements, and can be formatted as
an ASCII message or as a binary block. Binary data may be compressed
by a factor of two or four, for example to help reduce the traffic on a busy
USB hub. Depending on the model, the field values can be returned in
Tesla, mTesla, µTesla, nTesla, Gauss, kGauss, mGauss, equivalent proton
NMR frequency, or raw ADC values. A timestamp (in ns) and temperature
(arbitrary units, not calibrated) can also be read out.
3-2 INTERFACE
•USB interface:
Compliance with the USB 2.0 mechanical, electrical and protocol standard
provides basic connectivity with any USB-capable computer. The
instrument supports USB full-speed communication (12 Mbps).
•Standardized USB class driver:
Compliance with the USB Test & Measurement Class (USBTMC) allows
the instrument to be connected without installing a custom USB driver. All
that is required is a generic class driver for test and measurement
equipment, as provided by suppliers of instrumentation software. The
software supplied with this instrument includes the National Instruments
USBTMC driver.
•Standardized IEEE488.2 protocol:
Compliance with the USB488 protocol specification for USBTMC provides
all the capabilities of an IEEE488 instrument on the USB bus. IEEE488,
derived from HPIB/GPIB, is the world’s most widely used instrumentation
protocol. IEEE488 compliance allows any VISA library (Virtual Instrument
Software Architecture) to control every aspect of the instrument. The
software supplied with the instruments includes the National Instruments
VISA Runtime library.

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•Standardized instrument command protocol:
The SCPI standard (Standard Commands for Programmable Instruments)
is the standard developed and used by large instrumentation
manufacturers such as Tektronix and HP/Agilent, and provides a
programming interface familiar to many instrumentation system
programmers.
3-3 PROBE MECHANICAL DESIGN
•Protection for the sensor:
Magnetic sensors are sensitive electronic components. The plastic cover of
the THM1176-MF, -HF and -LF protects their Hall sensors from the bumps
and scrapes of normal use. For the THM1176-MF and -HF, the sensor
packaging provides effective protection even with the cap removed (see
below). However, the THM1176-HFC lacks all such protection; please note
the special handling precautions in Section 2-4, Precautions. The TFM1186
sensor is relatively large and mechanically very robust.
•Small gaps:
The THM1176-MF, -HF and -LF probes are 10 mm thick. To measure in a
smaller gap, the THM1176-MF or -HF probe cap can be removed, reducing
the thickness to 4.1 mm. If needed, the THM1176-MF or -HF sensor – only
2.3 mm thick – can be separated from the probe plastic; note, however,
that the sensor wires are delicate and can easily be broken. For even
smaller gaps, use a THM1176-HFC, whose probe is only 0.5 mm thick.
•Stationary installation (THM1176-MF and -HF only):
Removing the cap also reveals a mounting point that allows the probe to be
permanently mounted or attached to a scanning arm. The exact position of
the field-sensitive point can be determined by optical sighting.

THM1176/TFM1186 User’s Manual v 1.3 r 1.2 – 04/14 Copyright © 2014 Metrolab Technology SA
www.metrolab.com
15
3-4 DESKTOP KIT
•A complete magnetic field measurement kit:
The desktop kit includes everything except the computer: the
THM1176/TFM1186 instrument, calibration, a zero-Gauss chamber (not for
TFM1186 – see Section 2-4), the National Instruments VISA runtime library
and USBTMC driver, turn-key measurement software, all the LabVIEW
source code, software licenses from Metrolab as well as National
Instruments, and this manual.
•Measurements out of the box:
Install the VISA Runtime library and measurement software, and plug in the
THM1176/TFM1186. The software allows you to:
oDisplay B, Bx, Byand/or Bz, either numerically or on a graphical
display;
oDisplay either the raw data or computed peak-to-peak, standard
deviation or spectral values;
oVisualize the direction of the B-vector relative to one of the probe’s
axes;
oSet the units in which the results are displayed, including raw ADC
value;
oCapture the maximum field value;
oHold (freeze) a given measurement;
oRecord data to a file; and
oReplay a recorded file.
A Setup page allows you to:
oChoose amongst multiple instruments plugged into your PC;
oDisplay information about your instrument, such as model and serial
numbers, version numbers of the electronics, probe and firmware,
and the date of the last calibration;
oDisplay version information about the software;