The Set-up consists of the following
1. Hall probe (Ge:p type)
3. Temperature sensor
4. Hall Effect Set-up, Model : DHE-22
5. Electromagnet, EMU-50V
6. Constant Current Power Supply, DPS-50
7. Digital Gaussmeter, DGM-102
1. HALL PROBE (GE : P-TYPE)
Ge single crystal with four spring type pressure contact is mounted on a glass-epoxy strips. Four leads are
provided for connections with the probe current and Hall voltage measuring devices.
It is a small oven which could be easily mounted over the crystal or removed if required.
Size : 35 x 25 x 5 mm (internal size)
Temperature Range : Ambient to 100°C
Power requirement : 12 W
3. TEMPERATURE SENSOR
Temperature is measured with Cromel-Alumel thermocouple with its junction at a distance of 1 mm from the
4. HALL EFFECT SET-UP, MODEL : DHE-22
The set-up, DHE-22 consists of two sub set-ups, each consisting of further two units.
(i) Measurement of Probe Current & Hall Voltage
This unit consists of a digital millivoltmeter and constant current power supply. The Hall voltage and probe current can be read on the same digital panel meter through a selector switch
a) Digital Millivoltmeter
Intersil 31⁄2 digit single chip ICL 7107 have been used. Since the use of internal reference causes the degradation in performance due to internal heating an external reference have been used.
Digital voltmeter is much more convenient to use in Hall Experiment, because the input voltage of either polarity can be measured.
Range : 0-200mV (100μV minimum)
Accuracy : ±0.1% of reading ± 1 digit
(b) Constant Current Power Supply
This power supply, specially designed for Hall Probe, provides 100% protection against crystal burn-out due to excessive current. The supply is a highly regulated and practically ripple free dc source.
Current : 0-20mA
Resolution : 10μA
Accuracy : ±0.2% of the reading ±1 digit Load regulated : 0.03% for 0 to full load Line regulation : 0.05% for 10% variation