As many of you know, I use a CellSensor EMF detector with the HDR. The EMF meter tells me the strength of the magnetic field being generated by the HDR as well as it helps me to locate a magnetic vortex grid point. It is important to find an area of magnetic anomaly to use the HDR over as it interacts with an existing natural vortex. Steven Gibbs warn me not to use an artificial vortex or grid point with the HDR.