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Part Number or Numbers

Monitoring Loops

• FESP 5133-7/41 – Circular Shielded Loop Sensor
 FESP 5133-9 – Circular Screened Coil
FESP 5133-1330 – Circular Coil

 FESP 5134-1 – Field Monitoring Loop
• FESP 5134-40 – Loop Sensor / Antenna


FESP 5133-7/41 

Schwarzbeck FESP 133-7_41 Circular Shielded Loop Sensor 

· Circular shielded loop sensor to determine the magnetic field strength

· 36 turns AWG 7/41

· diameter 133 mm

· distance gauge 7 cm included

· MIL 461E RE101 or RS101 alternative test procedures.


pdficon small Data Sheet FESP 5133-7/41


FESP 5133-9 – Circular screened Coil 

FESP 5133-9 - Circular screened Coil

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. 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).

Application as 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 fixed frequency) or directly proportional to frequency (at constant magnetic field strength).

Number of turns: 9
Wire diameter: 1.2 mm Cu
Maximum coil current: 11 A (5 min.)
Nominal coil current: 7 A continuous
Max. magn. field strength: 380.4 A/m (5 min.)
Nominal magn. field strength: 242 A/m continuous
Magnetic field strength, 1 A coilcurrent: (with 50 mm distance ring): 34.58 A/m
Current required for 1 A/m:
(with 50 mm distance ring)
28.9 mA
Flux density with 50 mA at 50 mm distance: 127 dBpT
Inner coil diameter: 133 mm
Medium coil diameter: 134.2 mm
Spacing coil center to measurement plane: 50 mm
Mechanical dimensions:  0.16 m x 0.2 m
Connector: N-jack
Usable frequency range: 10 kHz – 3 MHz
Inductance: ~ 20 μH
Resistance: 0.1 Ω
Weight: 0.8 kg
Standard: VG 95377 Part 13


 Schwarzbeck FESP 5133-9 Circular Screened Coil Data Sheet


FESP 5133-1330 – Circular Coil 

The handheld coil FESP 5133-1330 was designed for immunity testing against magnetic fields up to approx. 20 kHz. The coil has 225 turns of Cu-wire on 15 layers. There are spacers to provide a constant distance of 50 mm between coil center and EuT-surface. The generated magnetic fieldstrength is direct proportional to the coil current. Typical Applications are Immunity Tests according to the Measuring Method SF 01 G acc. to VG 95377 standard.


Medium coil diameter: 126 mm
Medium Coil Distance to Surface: 50 mm
Number of turns: 225
Wire Diameter: 2 mm
Mechanical Dimensions: 190 x 190 x 290 mm
Terminals: 4 mm Laborstecker
Usable Frequency Range: 0 – 20 (50) kHz
Inductance: 6.5 mH
Resistance: 0.5 Ω
Capacitance: 240-300 pF
Resonance Frequency: 120 kHz
Impedance: |Z|=42 Ω @ 1 kHz
Max. Current: 20 A
Max. Fieldstrength at 50 mmspacing: 17 kA/m
Max. magnetic fieldstrength at 1 A coil current in 50 mm distance: 858.2 A/m
Required Current for 1000 A/m in 50 mm distance: 1.165 A
Magnetic Flux Density at 1 A coil current in 50 mm distance: 1.078 mT
180.66 dBpT
Conversion Current-Magnetic Fielstrength: 58.67 dB/m
Weight: 5.3 kg
Standard: Measuring Method SF 01 G acc. to VG95377


 Datasheet FESP 51331330

FESP 5134-1 

Schwarzbeck Field Monitoring Loop FESP 5134-1
The magnetic, handheld field sensor coil FESP 5134-1 was designed to determine the magnetic fieldstrength during immunity tests.
The loop sensor consists of a single shielded turn and can be used up to 400 MHz. The FESP 5134-1 is intended to be used with 50  measuring equipment, e.g. spectrum analyzers or measuring receivers. Thanks to the shielded turn the loop sensor achieves high symmetry and good E-field rejection.

Typical applications are immunity tests acc. IEC 61000-4-39, several automotive standards, the measurement of human exposure limits acc. to ICNIRP, IEEE C.95- 2005, 26.BImSchV and many others.




Number of Turns:


Coil Diameter:

40 mm

Usable Frequency Range:

10 kHz -400 MHz

Nominal Frequency Range:

100 kHz – 300 MHz


ca. 125 nH


ca. 70 g


46 x 18 x 95 mm




pdficon small Schwarzbeck FESP 5134-1 Data Sheet



FESP 5134-40 

Schwarzbeck FESP5134_40 Loop Sensor Antenna 

· Loop Sensor / Antenna

· diameter 4 cm

· 51 turns

· 0 Hz to 150 kHz

· electrostatic shielding

· BNC jack


pdficon small Data Sheet FESP 5134-40