Instruction Sheet - 3B SCIENTIFIC PHYSICS U8404275 Mode D'emploi

3B SCIENTIFIC ® PHYSICS
Pendulum Rod with Angle Sensor U8404275

Instruction sheet

10/07 ELWE/ALF
1. Safety instructions
Caution: The pendulum pivots on two sharp nee-
dles that can cause injury.
•
When setting up the pendulum, make sure
that both needle bearings are properly in
the groove.
•
Make sure the pendulum is resting safely
and securely.
•
The pendulum bob must always be secu-
red by the knurled screw to stop it from
falling down.
2. Description
The pendulum rod with angle sensor is used to
study simple harmonic oscillations, damping by the
air resistance, coupled oscillations*, and Lissajous
figures*. (*requires two pendulum rods with angle
sensor).
The angle sensor allows the deflection of a weigh-
ted pendulum, for example, to be converted into
an electrical signal. For small deflections, the sen-
sor outputs a voltage that is proportional to
angle of deflection.
brass tube with a housing for its electronic compo-
nents screwed on. The brass rod is for securing to a
cross sleeve on a retort stand and has a V-shaped
groove at its front end in which the pendulum can
pivot.
The positions of the two bearings at the top end of
the pendulum are indicated by ring markings.
Between these two marks there is a Hall sensor,
which is orientated in such a way that when the
pendulum is in the rest position, the magnetic field
lines run along the plane of the sensor chip and no
Hall voltage is generated. When the pendulum is
deflected through an angle δ from the vertical
position, the sensor experiences a horizontal field
component, which causes a positive or negative
output voltage depending on the direction of the
deflection. The angle sensor is matched to the
magnet pair in the support at the top of the pendu-
lum, so that when the alignment is precisely ad-
justed with the pendulum in the rest position, the
output voltage at the BNC socket is close to zero. A
fine adjustment can then be achieved using the
offset adjuster.
Note: the matching of the pendulum support with
the the corresponding angle sensor is indicated by a
1
1 Angle sensor
2 Offset adjuster
3 Pendulum rod
4 Pendulum weight
5 Needle bearing
6 Plug-in power supply
It consists of a nickel-plated