The EM –6874 Loop is mainly used for uncalibrated substitution measurements of Shielding Effectiveness as described by Mil.Std. 285, IEEE Std. 299, and NSA65-6. It comprises a radiating element of a single turn 0.3m diameter wire which is electrostatically shielded. Field strength generated is directly proportional to current in loop. See specification below.
The antenna impedance is seen as a 600nH coil in series with a resistance of 2 Ω. The coil can take up to 20 amperes rms.