To determine the RF-induced heating of an active implant, it is necessary to measure the 3D distribution of the power deposition in the hotspot volume. By measuring the Erms distribution around a test object, different influences on the decay were investigated. It was shows that radial decay can be described with a single model along test object. This model is normalized to a defined distance. The measurement values along the TO at this distance, can be used to scale the model and the power deposition inside the hotspot volume can be calculated. This leads to an advantage in time saving.