How to choose the ideal equipment to measure electromagnetic fields in the presence of radars?

Get to know the commercial solutions of our partner Narda Safety Test Solution, leader in the detection and measurement of electromagnetic fields. 

The presence of radars in an electromagnetic field measurement environment requires prior theoretical considerations and specific measurement equipment, which meet certain requirements.

Specifically, in order to comply with the RD 299/2016 and RD 1066/2001 standards and the correct characterization of the spectrum, equipment is required that can measure RMS electric field with a weighting of 6 minutes and also comply:

  1. The peak value of the flux density is less than 1000 times the maximum regulatory value.
  2. That the equipment is able to measure with a processing time fast enough (or failing that, with MAX HOLD function), allowing to record that peak value during a train of pulses due to the rotation of the radar or its pulsed emission.

The parameters to be taken into account, therefore, are:

  • Scanning radar time, typically 25ms or less
  • Maximum expected signal level
  • Frequency of the signals to be measured

The choice of measurement equipment will therefore depend on all these factors, as well as the type of sensor (diode type sensors underestimate the measurement above 2GHz, and thermocouple type sensors are best suited to the RMS curve).

Depending on these parameters, the equipment or probes are as follows:

"signalshark NardaSTS"NBM550 with EF1891 probe (18GHz, diode type) -> allows an approach to RMS with negligible deviation in the environment of measurements from 2GHz and with small signal levels. For high signal levels, it produces some underestimation of the field value.   The NBM550 has a signal processing time of 270-350 ms, so the MAX HOLD function must be activated to capture the peak value during several sweeps.

NBM550 with EF5091 probe (300MHz – 50GHz, thermocouple type, dynamic range: 8 – 614 V/m) -> has diode type sensors up to 2GHz range and thermocouple type sensors up to 50GHz, which guarantee a perfect adjustment to the RMS regardless of the signal level (within its ranges: 8 – 614 V/m).

NBM550 with EF5092 probe (300MHz – 50GHz, thermocouple type, dynamic range: 18 – 1090 V/m) -> identical parameterization to the previous one but with dynamic range above in signal level.

RADMAN XT – personal dosimeter (1 MHz to 40 GHz, diode type) -> diode type sensors that adjust to RMS up to 2GHz and slightly underestimate the field level above that frequency. The big advantage is its sampling rate (30 ms), in line with the radar pulses, so the peak value is determined without using the MAX HOLD.

 

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