Field Analyzer NARDA EFA200::


  • NISV, 26.BImSchV. , SUVA, BGV B11, compliant measurements
  • Sensor integrated coil system (B-Field), directional characteristic, selectable triaxial (isotropic) or single-axis
  • Broadband frequency range, selectable 5 Hz to 2 kHz, 30 Hz to 2 kHz, 5 Hz to 32 kHz or 30 Hz to 32 kHz
  • Frequency range – Band pass / Band-elimination filter, selectable 15 Hz to 2 kHz
  • Measurement size, selectable effective value (averaging time 1 sec) or peak value (phase accurate)
  • Measuring range 4 nT (100 cm2 probe) to 32 mT
  • STD-assessment, frequency range 5 Hz to 32 kHz
  • STD-measuring range (ICNIRP occ.) < 0,4 % to 200 %
  • FFT-frequency range 5 Hz to 2 kHz or 40 Hz to 32 kHz
  • Measurement data memory up to 3600 single values or 3600 single values or 22 spectra

Example measurements in open-plan office

Electronic fields measurements with EFA200 in an open-plan office. The measured values were then programmed into the calculation and visualization software EFC400. The field strengths can therefore be visualized as isolines.


Isotropic magnetic field probe 100cm²::


SondeIsotrope 100cm2 probe
The isotropic magnetic field sensor with 100 cm² coil surface can be plugged into the NARDA EFA200 and is characterized by a high level of sensitivity. The probe is used depending on the application and standard, for the measurement of inhomogeneous magnetic fields.
Without probe  
With probe       
Measuring range 50/ 60Hz:
50nT to 10 mT resp. 5nT to 10mT
with selectiv filter
10nT to 10 mT resp. 1nT to 10mT
with selectiv filter



Spectramag-6, Bartington

This portable 6-channel 24-bit data acquisition unit is used for the simultaneous three-dimensional registration and analysis of the magnetic field, vibrations and acoustic data.
The six input channels of the Spectramag-6 provide synchronous digitization of the output signals of magnetic field, acceleration and acoustic sensors. In combination with a PC, the device can record data with rates of up to 10kHz. The supplied software stores and displays the data in time and frequency range up to 3.5 kHz.

  • Sensitivity: 10pT (Pico Tesla)
  • DC and AC field measurements
  • Sampling interval 100µs to 10s
  • Network independent and network dependent operation
Typical applications:
  • Site survey for electron microscopes
  • Measurement of the damping of shields
  • Interference frequency analysis

Example measurements for electron microscope

Measurements of the electromagnetic field strength at the location of an electron microscope. With measurements it could be demonstrated, that the field strengths of the environment field are over the interference limit of the microscope.

For comparison, the measurement was performed with switched off (lower charts, Input 2) and with switched on (top charts, Input 1) compensation. In the lower diagram on the right, the interference frequencies with dominant 50Hz and 3., 5., 7. and 9. harmonious are well visible. In the top charts, with turned on compensation, it can be well documented, that the field strengths are reduced to non-critical values.

Microscope at ETH Measurement of magnetic field strengths

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