The magnetic, handheld coil FESP 5133 was designed to generate defined magnetic field strength in the audio frequency range up to 3 MHz. The main application is immunity testing against magnetic fields according to  VG 95377 Part 13 and many others. Depending on the current source characteristics magnetic fields up to 400 A/m can be generated for a short time.

The generated magnetic field strength is proportional to the coil current. The 50 mm distance ring is supplied to ensure a well-defined spacing between the coil plane and the equipment under test (EuT)-surface. There are further rings available on request in order to provide a certain scaling between coil current and magnetic field strength (e.g. 1 Amp coil current = 10 A/m field strength).

The main part of the generated magnetic field is perpendicular (orthogonal) to the surface of the equipment under test, i.e. in the same direction as the 22 mm handle.

The achievable accuracy for generating defined magnetic fields depends on the accuracy of current measurements. In some cases (with moderate field strength requirements) it may be advisable to use a well-known series resistor and measure the voltage across this resistor. The resistor can be scaled in a way to obtain a convenient voltage reading which corresponds to the generated magnetic field. The larger the series resistor compared to the inductance, the more frequency-independent characteristics will be achieved (but the efficiency of field strength reduces)

Application as a magnetic field probe:

The FESP 5133-9 can also be used to measure existing magnetic fields. The open-circuit output voltage is directly proportional to the magnetic field strength (at a fixed frequency) or directly proportional to frequency (at constant magnetic field strength).

Specifications: