Impedance converter with high-resistance input for measuring extremely small charges and currents. The input signal is converted into a proportional voltage, which can then be measured with an external voltmeter. During the measurement the potentials of the electrometer and the experimenter must be matched by using a metal rod connected to earth. Includes a 12-V AC plug-in power supply.
Possible experiment topics:
Measurement of charge and voltage in electrostatics
Measurement of charge and voltage for a plate capacitor
Ionisation of air by burning gases or α radiation
Hallwachs effect (external photoelectric effect)
Specifications:
Electrometer gain factor: 1.00
Input resistance: >1012 Ω
Output resistance: <1 kΩ
Input current: <10 pA
Input capacitance: <50 pF
Max. output voltage: ±8 V
Resistance to excess voltage: 1 kV (from low-resistance sources), 10 kV (from high-resistance sources)
Supply voltage: 12 V AC