3B Scientific Digital Teslameter with Probe 20 mT, 200 mT (115 V, 50__60 Hz) - Manual (Page 4)

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com
Subject to technical amendments
© Copyright 2009 3B Scientific GmbH
2.1 Operating controls and connections
1 Connecting socket for magnetic field probe
2 Digital
display
3 Measurement range selector, 20 mT
4 Measurement range selector, 200 mT
5 Measurement mode switch, axial (B
X
) and tangential (B
Z
)
6 Zero adjustment knob for B
X
with LED indicator
7 Zero adjustment knob for B
Z
with LED indicator
8 Output socket for axial mode B
X
9 Earth (ground) socket
10 Output socket for tangential mode B
Z
11 On/off switch
Magnetic field probe: 1 axial Hall probe (x-direction), 2
tangential Hall probe (z-direction), 3 probe carrier
3. Technical data
Measurement range 20 mT
Resolution: 0.01 mT
Accuracy: 2 % ±3 digits
Measurement range 200 mT
Resolution:
0.1 mT
Accuracy : 2 % ±1 digits
Digital display: 3½ digit LCD with sign
showing field direction
Height of digits: 13 mm
Input: BNC socket
Output: 4 mm safety sockets
Output voltage: 10 mV / mT (20 mT)
1 mV / mT (200 mT)
Dimensions of unit: 205 x 230 x 85 mm³
Dimensions of probe: 360 x 15 x 25 mm³
4. Operation
4.1 Zero adjustment
It is recommended that the zero adjustment should
be carried out with the measurement range set to 20
mT. If the range is subsequently changed to the larger
one, it is not necessary to repeat the adjustment.
If the magnetic field of a permanent magnet is to be
measured, the zero adjustment must be carried out at
a sufficiently large distance from the magnet.
If the fields of current-carrying conductors are to be
measured, it is recommended to first switch off the
magnetic field current and position the probe at the
point where the measurement is to be made.
• Connect the magnetic field probe to the probe socket 1.
• Select the 20 mT measurement range.
• Rotate the zero adjustment knob until the
indicated field value is zero or as small as possible.
4.2 Measurement of axial magnetic fields
The axial Hall probe measures the component of the
magnetic flux density along the direction of the probe
axis.
It is also possible to determine the direction of the
magnetic field: if the field lines are directed towards the
probe carrier (e.g., like the field coming from the north
pole of a bar magnet), the indicated value is positive,
whereas for the opposite direction it is negative.
4.3 Measurement of tangential magnetic fields
The tangential Hall probe measures the component of
the magnetic flux density in the direction
perpendicular to the carrier plate.
It is also possible to determine the direction of the
magnetic field: a positive reading indicates that the
field entering the tangential probe comes from the
direction of the carrier surface with the scale
markings, whereas a negative reading indicates that it
is in the opposite direction.
4.4 Using the analogue output signals
The output sockets (8, 9, 10) provide voltages
proportional to the magnetic field components that
can be fed to external measuring devices (data
loggers, XY graph plotters, or analogue multimeters).
The output voltage corresponds to the digital reading.
It amounts to 10 mV per mT field value in the 20 mT
operating range and 1 mV per mT field value in the
200 mT operating range.