FESP 5139 - Radiating Loop


FESP 5139 - Radiating Loop

  • FESP 5139


The magnetic, handheld coil FESP 5139 was designed to generate defined mag-netic fieldstrength in the frequency range from DC up to 5 (7) MHz. The main application is immunity testing against magnetic fields according to IEC 61000-4-39.

Depending on the current source char-acteristics magnetic fields up to 360 A/m can be generated for a short time. The generated magnetic fieldstrength is pro-portional to the coil current. A distance ring allows a precise spacing of 50 mm between coil and EUT surface. Other distance rings can be used to scale the current-fieldstrength ratio. The highest fieldstrength levels can be achieved using the shortest ring. There are further rings available on request in order to provide a certain scaling between coil current and magnetic fieldstrength (e.g. 1 A coil current = 20 A/m fieldstrength).


Application as Sensor for Magnetic Fields:

The FESP 5139 can also be used to measure existing magnetic fields. For this purpose the FESP 5139 is connected to a frequency selective 50 Ohm measuring instrument e.g. a spectrum analyzer or a measuring receiver.


Number of turns: 3
Wire diameter: 1 mm Cu
Maximum Coil Current: 12 A (5 min.)
Nominal Coil Current: 8 A continuous
Maximum magnetic Field Strength:(without distance ring, in coil center) 360 A/m (5 min.)
Nominal Magnetic Field Strength with 50 mm distance ring: 85 A/m continuous
Magnetic Fieldstrength, 1 A Coil Current:
(with 50 mm distance ring)

10.61 A/m

Current required for 1 A/m:
(with 50 mm distance ring)

94.25 mA
Medium coil diameter: 100 mm
Spacing coil center to measurement plane: 50 mm
Mechanical Dimensions: 11 x 11 x 21 cm
Connector: N-female
Usable Frequency Range: 0 - 5 (7) MHz
Inductance: 2.3 μH


0.47 kg


Datasheet FESP 5139