5 Electricity and Magnetism 5.6 Sources of Magnetic Field
Determination of the earth's magnetic field
P2430100
Linear function to determine the horizontal component hBE of the magnetic flux density of the earth-magnetic field.
Principle
Helmholtz coils, one pair
A constant magnetic field, its magnitude and direction known, is superimposed on the unknown earth magnetic field. The earthmagnetic field can then be calculated from the magnitude and direction of the resulting flux density. Tasks 1. The magnetic flux of a pair of Helmholtz coils is to be determined and plotted graphically as a function of the coil current. The Helmholtz system calibration factor is calculated from the slope of the line. 2. The horizontal component of the earth-magnetic field is determined through superimposition of the Helmholtz field. 3. The angle of inclination must be determined in order to calculate the vertical component of the earth-magnetic field. What you can learn about ▪ Magnetic inclination and declination ▪ Isoclinic lines, Isogenic lines, Inclinometer ▪ Magnetic flow density, Helmholtz coils
Function and Applications Helmholtz coils, one pair to generate a homogeneous magnetic field. Especially with narrowbeam tube for e/m determination.
Main articles Teslameter, digital Helmholtz coils, one pair Power supply, universal Magnetometer Hall probe, axial Rheostat, 100 Ohm , 1.8A Digital multimeter 2010 Barrel base PHYWE Stand tube
Equipment and technical data 13610-93 06960-00 13500-93 06355-00 13610-01 06114-02 07128-00 02006-55 02060-00
1 1 1 1 1 1 1 1 1
▪ Two identical coils each on standbase with numbered 4mm sockets ▪ Removable busbars with holder for narrow beam tube ▪ Coils can be used indivdually and at any distance. ▪ Coil diameter: 400 mm, Number of windings: each coil 154 ▪ Coil resistance: 2.1 Ohm ▪ Max. current per coil: 5 A, Max. flux density (5A): 3.5 mT 06960-00
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