Vernier MG-BTA User Manual

Magnetic Field Sensor

(Order Code MG-BTA)

The Vernier Magnetic Field Sensor measures a vector
component of the magnetic field near the sensor tip.
The tip can be adjusted, allowing the user to
measure fields that are parallel or perpendicular to the long axis of the sensor. The
Magnetic Field Sensor can be used for a variety of interesting experiments
involving magnetic fields.

 Measure and study the Earth’s magnetic field.
 Determine the direction of magnetic north.
 Study the magnetic field near a permanent magnet.
 Mea sure the fie ld near a curren t-carry in g w ire.
 Measure the field at the opening of a solenoid.

Note: Vernier products are designed for educational use. Our products are not
designed nor are they recommended for any industrial, medical, or commercial
process such as life support, patient diagnosis, control of a manufacturing
process, or industrial testing of any kind.

Compatible Software and Interfaces

See www. vern ier. co m/manu als /mg- bt a fo r a l ist o f in terfaces and softw are compatibl e
with the Magnetic Field Sensor.

Getting Started

1. Connect the sensor to the interface (LabQuest Mini, LabQuest 2, etc.).

2. Start the appropriate data-collection software (Logger Pro , Logger Lite,
LabQuest App) if not already running, and choose New from File menu.

The software will identify the sensor and load a default data-collection setup. You
are now ready to collect data.

If you are collecting data using a Chromebook™, mobile device such as iPad

®

or
Android™ tablet, or a Vernier wireless sensor or interface, please see the following
link for up-to-date connection information:

www.vern ie r.co m/st art/mg- bt a

Using the Sensor

Connect the sensor following the steps in the Getting Started section of this user
manual.

Use the switch on the sensor shaft to select an appropriate range.

 The 6.4 mT range is used to measure relatively strong magnetic fields around

permanent magnets and electromagnets.

 The 0.32 mT range is used mainly to measure the magnetic field of the Earth

and very weak fields. It can be used for other magnets, but the sensor must
remain in one position so that the reading is not affected by the background
field of th e Ea rth .

Videos

View videos related to this product at www.vern ier. com/mg-b t a

Calibration

You should not have to perform a new calibration when using the
Magnetic Field Sensor. We have set the sensor to match our stored calibration
before shipping it.

It is not practical to calibrate the Magnetic Field Sensor without reference to a
known source of magnetic field. It is useful, however, to zero the
Magnetic Field Sensor. Position the sensor and zero it using your data-collection
software. Move the magnetic field source, and not the sensor, to explore the spatial
variations of the field.

Moving the sensor will upset the zero since the background magnetic field in your
lab probably varies with position. For experiments measuring the spatial variation
of a magnetic field, it is better to zero the sensor and then move the source to
various positions.

Specifications

13-bit resolution ±0.32 mT range: 0.0001 mT

±6.4 mT range: 0.002 mT

12-bit resolution ±0.32 mT range: 0.0002 mT

±6.4 mT range: 0.004 mT

10-bit resolution ±0.32 mT range: 0.0008 mT

±6.4 mT range: 0.016 mT

Stored calibration value
(±0.32 mT range in millitesla)

slop: 0.160 mT/V

intercept: –0.320 mT

Stored calibration value
(±6.4 mT range in millitesla)

slope: 3.225 mT/V

intercept: –8.063 mT

Stored calibration value
(±0.32 mT range in gauss)

slope: 1.6 gauss/V

intercept: –3.2 gauss

Stored calibration value
(±6.4 mT range in gauss)

slope: 32.25 gauss/V

intercept: –80.625 gauss

How the Sensor Works

The sensor uses a Hall-effect transducer. It produces a voltage that is linear with
magnetic field. The sensor measures the component of the magnetic field that is
perpendicular to the white dot on the end of the sensor tip. The reading is positive
when the white dot on the sensor points toward a magnetic south pole.

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The switch on the sensor shaft is used to select the range. On the 6.4 mT range,
each volt measured by the transducer represents 32 gauss (3.2 × 10

-3

tesla). The

range of the sensor is ±64 gauss or ±6.4 × 10

-3

tesla. On the 0.3 mT range, each

volt measured represents 1.6 gauss (1.6 × 10

-4

tesla). The range of the sensor is

±3.2 gauss or ±3.2 × 10

-4

tesla.

If the sensor tube is held vertically with the tip horizontal, and rotated until the
maximum voltage is found, the tip with the white dot will point to magnetic
north. The magnetic inclination in your area can be found by holding the tube so
that the white dot is facing north, and rotating the sensor end of the tube down
until the voltage reaches a maximum. The angle of the tip from the vertical
position is the magnetic inclination. Note that the north pole of a freely suspended
magnet points north, since the magnetic pole of the Earth in the northern
hemisphere is a south magnetic pole.

Troubleshooting

If you are getting unexpected or unusual readings from the Magnetic Field Sensor,
first confirm that the range setting is appropriate for the experiment. The ±6.4 mT
range is used to measure relatively strong magnetic fields around permanent
magnets and electromagnets; the ±0.32 mT range is used to measure the magnetic
field of the Earth and very weak fields. If you are using the ±0.32 mT range for
investigating permanent magnets, make sure that the sensor remains in one
position so that the reading is not affected by the background field of the Earth.

For other troubleshooting tips and FAQs, see

www.vern ie r.co m/til/1420

Repair Information

If you have watched the related product video(s), followed the troubleshooting
steps, and are still having trouble with your Magnetic Field Sensor, contact
Vernier Technical Support at [e-mail] or call 888-837-6437. Support
specialists will work with you to determine if the unit needs to be sent in for
repair. At that time, a Return Merchandise Authorization (RMA) number will be
issued and instructions will be communicated on how to return the unit for repair.

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Warranty

Vernier warrants this product to be free from defects in materials and workmanship
for a period of five years from the date of shipment to the customer. This warranty
does not cover damage to the product caused by abuse or improper use. This
warranty covers educational institutions only.

Vernier Softwar e & T echnology

139 79 SW Millikan Wa y • Be aver ton , OR 97005- 2886

Toll Free [phone] • ( 503) 277- 2299 • FAX [phone]

[e-mail] • www.vernier.com

Rev. 2/8/16

Logger Pro, Logger Lite, Vernier LabQuest 2, LabQuest Mini, and other marks shown are our trademarks or
registered trademarks in the United States.

All other marks not owned by us that appear herein are the property of their respective owners, who may or may
not be affiliated with, connected to, or sponsored by us.

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