3B Scientific Inclination Instrument - Manual (Page 2)

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com
Subject to technical amendments
© Copyright 2008 3B Scientific GmbH
3. Operation
3.1 General precautions
• Protect the instrument from moisture, dust and
mechanical shocks.
• Avoid touching the magnet needle.
The geometry of the earth’s magnetic field lines can
be greatly altered by static magnetic fields, steel
frames of laboratory benches and equipment, and
steel supports in the floor, ceiling and walls of
buildings. For this reason the measured angles may
sometimes differ widely from the expected values.
3.2 Measurement of the inclination
The magnet needle aligns itself along the direction
of the earth’s magnetic field.
• With the scale ring in the horizontal plane, turn
the instrument so that the blue end of the
magnet needle is at 0° (the blue end of the
needle is its north-seeking pole).
• Next turn the cradle through 90° (the plane of
the scale ring is then vertical). The blue end of
the magnet needle is inclined downwards.
The angle between the magnet needle and the
horizontal plane is called the inclination. It differs
from place to place. At a latitude of about 50° north
(Europe) the inclination is 63° to 68°.
3.3 Magnetic effect of an electric current
In order to carry out the experiment, a variable DC
current source is also needed, such as:
1 DC power supply 0 - 20 V, 0 - 5 A (230 V, 50/60 Hz)
U33020-230
or
1 DC power supply 0 - 20 V, 0 - 5 A (115 V, 50/60 Hz)
U33020-115
• With the scale ring in the horizontal plane, turn
the instrument so that the blue end of the
magnet needle (its north-seeking pole) is at 0°.
• Connect the sockets on the instrument to a
variable DC current source.
As the current is increased, the needle is deflected
increasingly from its original direction.
When the polarity is reversed, the direction of the
deflection changes.