## 3 Results of the Assessment Process  
Measurement equipment was the Extech 480826 and Extech 450 m, certified for low-frequency EMF, according to all regulations. The electric field measurements have the highest degree of relevance for the configuration of the connection scheme at the moment of the measurements. Magnetic field measurements have a lower degree of relevance, given the variable loading conditions of the current path. The calculation model of the magnetic field produced by a high voltage line is based on a quasi-static approximation. Only the longitudinal current is considered and the transversal current is totally neglected. Considering a system of three-phase lines, the total magnetic field is obtained from the superposition of the fields, taking into account the phase difference between the currents traveling lines. In general, the magnetic field generated by the three-phase lines is elliptical. The calculation of the magnetic field is performed in a plane perpendicular to the conductor axes and it is based on the image method for conductors replacing the ground plan with a different virtual one, located at a certain depth below ground level. The mandatory characteristics of the measuring equipment are:  
* Common characteristics relative to both measurements, the electric and magnetic field:
* Mediation time for displaying the effective value: 1 s
* Maximum instantaneous peak values evaluated over the last 250 ms
* Data acquisition rate (refresh time) of the measuring system: 250 ms
* Possibility of storing at least 1000 values for each measuring unit (electric or magnetic field; the electric field measuring unit can be programmed and can operate independently from the base unit, with its own memory). * Specific characteristics for the electric field measurement:
* Triaxial probe, mountable on a tripod, connected by optical cable to the base unit. It can evaluate the value of the electric field strength components parallel to the coordinate axes, as well as the resulting value (isotropic);
* Measuring range: 10 V/m..100 kV/m;
* Measurement precision class at least 3%. * Specific characteristics for measuring the magnetic field:
* Triaxial probe, incorporated in the basic unit. May indicate the value of the magnetic flux density components parallel to the coordinate axes, as well as the resulting value (isotropic);
* Measuring range for the magnetic field (expressed in values of magnetic flux density in the air): 100 nT..50 mT;
* Measurement precision class at least 5%. The effective value, the maximum, and the isotropic value (the result of the values on the three axes) were measured with at least 3 s of waiting time before starting each procedure. In addition to the measurement uncertainty, inherent to the device and specified by the manufacturer, some other factors highly influence the measurement process:  
* When measuring the electric field:
* humidity (measurement errors increase with increasing relative humidity);
* temperature (the low temperatures which determine condensation formation on the insulated parts of the equipment can influence the measurements);
* the harmonics of the industrial frequency voltage (for the working procedure described above, these uncertainties are insignificant);
* the inhomogeneity of the electric field. * When measuring the magnetic field:
* non-uniformity of the magnetic field
* the harmonics of the industrial frequency voltage (for the working procedure described above, these uncertainties are insignificant);
* the non-orthogonality and the relative position of the measuring coils on the three coordinate axes (insignificant influences, small, compared to the uncertainty guaranteed by the manufacturer);
* the inhomogeneity of the electric field. All the measurement processes described in this paper are related to the Fintinele power station, located in South Transylvania, Romania, belonging to the National Power Grid Operator, Transelectrica S.A. Figure 3 presents the layout of the Fintinele power station.