We bougth a Spectran NF-5020 for measuring electromagnetic fields in electric substations. We usually measure the electromagnetic fields at 50 Hz and without an external antenna. I was wondering if the measured values would be more accurate if we would do the measures with an external antenna. What do you recommend me?
Which type of antenna is suitable to measure electric and magnetic fields at 50 Hz in an electric substation?

The NF-5020 already includes a very good internal 3D magnetic field sensor and a internal electric field sensor.
To get even better results you can upgrade to the new NF-5030 which includes our new 3D magnetic field sensor with improved electric field shielding.

We will also offer a new probe set in about 6-8 weeks. It will include 4 different magnetic field probes (which offer a very good shielding against electric fields) and a special electric field probe. You can connect those to all our SPECTRAN units.
This set will offer the best possible sensitivity in the low frequency range. We will also offer a new 40dB preamplifier for it which will boost the sensitivity even more.