#### Measuring earth's magnetic field (31.869 µT) using Helmholtz coil pair. Accurate microcontrolled magnetic field teslameter (our own product)...

**Possible Experiments**
- Measuring magnetic flux of helmholtz coil and calibration
- Measuring parellel magnetic field of Earth and measuring perpendicular component

**Standard Equipment**
1 Helmholtz coil pair, adjustable current supplyı, reoasta, digital teslameter (with zeroing pot.), Hall probe, multimeter, compass, connection rod.

**Technical Information **
Earth includes rotating magma at its center and has a magnetic moment due to this motion. Earth's magnetic field is similar to that of magnetic dipole. The axis of this dipole has an angle of 11.5 degrees with the rotational axis of the Earth. The dipole's magnetic dipole moment is µ=8.0x1022 J/T. This causes that geographical north-south poles are at different locations from that of magnetic poles. If parallel, perpendicular components of theis field and deviation angle are calculated one can get magnetic field vector. To measure this field, one can use Helmholtz coil pair at 20-30 cm radius and 1-2 mm diameter copper windings. When current is provided at coils a magnetic field of: B=0.715 µ0 n I /R where n is number of windings and R is the radius of coils. First, the current is increased and magnetic field is measured between 0 and nearly 3-10 mT. When B=kI graph is drawn, the straight line is exptrapolaed through weak field region. Here "k" is the slope and called calibration constant. Using weak currents and the deflection in the compass, the magnetic field can be calculated...