Modern Gaussmeters have an appearance similar to a multimeter, and allow a user to measure the magenetic field of intensity typically in milliGauss or microTeslas units.

Since Magnetic and Electric fields are related to each other through the laws physics, (that is the flow of electrons through a wire generates a magnetic fields surrounding the device that often extends beyond the casing of the device), It is possible to use a Gaussmeter to detect the presence of near by electric field produced by electric transmission equipment, power lines, microwave ovens, air conditioners, refrigerators, computers monitors, and all form of video or audio electronics device such as cellphones.

Scanning the room with a Guassmeter for measuring the magnetic field generated by electronics is the best way to find a hidden cellphone bug. Electromagnetic Radiation meters are less effective at finding cellphone bugs since they can only detect a hidden cellphone when the cellphone is transmitting which maybe only once a day for a brief and intermittent periods of time to download tracking data. For faster detection it is best to turn off the building power supply or disconnect car batteries when sweeping for cellphone bugs to avoid magnetic fields generated by friendly electronics and electrical fixtures. Disconnecting the main cable and phone line also aides in bug sweeps since they wires are hot with signalling fields. — Preceding unsigned comment added by Brutemenu (talk • contribs) 19:46, 3 March 2014 (UTC)[reply]