This is carried out by an engineer using the range of Environmentor or Narda equipment listed in section 100. The engineer will use an orthogonal sensor to walk around the prescribed area and report on any number of readings that the customer requires over a specified period of time. A report will then be compiled within a few working days on the levels found in units or micro or milli-Tesla. There are two basic bands: 5Hz-2kHz and from 2kHz-400kHz. Filters can be used to specifically identify levels at 50Hz, if required.
This test forms part of the Health and Safety requirements for personnel working in or visiting such environments especially where Heart Pacers are worn.