Elwe Didactic GmbH • Steinfelsstr. 6 • 08248 Klingenthal • Germany •
www.elwedidactic.com
3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany •
www.3bscientific.com
Subject to technical amendments
© Copyright 2010 3B Scientific GmbH
2. Contents
1 Base plate
1 Stand rod
1 Start fitting
3 Steel balls, 16 mm dia.
1 Allen key
3. Technical data
Range of heights
20 to 960 mm
Switch contacts:
Start:
Mechanical
Stop:
Electronic
Dimensions:
200 x 130 x 730 mm
3
4. Set-up
•
Insert the stand rod into the socket in the base
plate as far as it will go, and turn it so that the
scale faces towards the red contact plate.
•
Tighten the fixing screw using the Allen key
provided.
If the stand rod has been set up correctly, the scale
will be exactly at the correct height and the in-
strument is ready for operation.
Fig. 1 Setting up the stand rod
5. Operation
The following equipment is also required to per-
form the experiment:
1 Digital counter/timer
U8533341
1 Set of experiment leads
U13811
•
Connect the free-fall apparatus to a timer.
Make sure you keep to the colour coding of the
sockets.
•
Set the release lever and adjust the height of
fall.
The height of fall can be read off the scale on the
rod and is referenced to the top edge of the bore
on the start fitting (see Fig. 2). The reading on the
scale corresponds to the distance covered, i.e. the
distance between the ball and the contact plate at
the bottom.
•
Place the steel ball between the contact pins
from below so that it is held in place by the re-
taining lug when the latter is pressed down.
•
Allow the ball to fall by pushing lightly on the
release lever.
For optimum precision and reproducibility, the
release must be operated gently and carefully.
The micro-magnet moves away from the surface of
the ball. The start contact opens at the instant the
ball begins to fall.
When the ball hits the contact plate at the bottom,
the stop contact is opened briefly and the time
measurement is stopped.
Fig.2 Adjusting the height of fall
