3B Scientific Electrometer Box - Manual (Page 2)

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com
Subject to technical amendments
© Copyright 2009 3B Scientific GmbH
6. Examples of use
Suitable for quasi-static measurement of voltages up
to ±8 V, for high-resistance measurement of voltages
greater than ±8 V with the aid of a resistive voltage
divider, for quasi-static measurement of voltages
greater than ±8 V with the aid of a capacitive voltage
divider, for measuring very small currents with the
aid of a high-resistance shunt and for measuring very
small charges.
7. Sample experiment
Measuring charges in electrostatics
Apparatus required:
1 3B NETlog TM U11300
1 Electrometer box U11375
1 Faraday cup U8496460
1 Capacitor 1 nF, 160 V 1642411
2 Friction rods U11053
1 Experiment lead, black, 75 cm U13800
1 Crocodile clip 4 mm U13805
1 Cloth for rubbing rods
• Set up the experiment as shown in Fig. 1.
• Plug the Faraday cup and the 1 nF capacitor into
the 4 mm sockets provided.
• Plug the experiment lead into the green-and-
yellow 4 mm socket on the side of the box.
• Attach the crocodile clip to the free end of the
experiment lead.
• Switch on the 3B NETlog TM unit and wait for it to
detect the electrometer box.
• Hold the crocodile clip in one hand and, without
releasing it, discharge the Faraday cup.
• With the other hand lower the test object (e.g., a
friction rod that has been rubbed) into the
Faraday cup.
• Observe the effects of the charge transfer as
shown by the changes in the voltage reading on
the 3B NETlog
TM unit.
Fig. 1 Experiment set-up for measuring charges in
electrostatics