Among its line of handy magnetic field testers, Triplett Test Equipment & Tools has one with a mode for detecting magnets. Its handheld ET350 combines a non-contact voltage and a magnetic field detector in a pen-style format. It detects low voltage AC wiring commonly found in doorbell circuits, thermostats, control circuits and video surveillance camera power. It also can quickly determine the presence of magnetic fields whether AC, DC or permanent, lighting up yellow to signal the user.
Others from the company include its EMF20 Magnetic Field Meter which measures electromagnetic field from 30 to 300Hz. The meter is used typically to measure extremely low frequency from electric transmission equipment, power lines, microwave ovens, air conditioners, refrigerators, computer monitors, fans, hairdryers and many other appliances. Measurements can be displayed in milligauss or µTesla. It features a single axis sensor, with about 2.5% accuracy,
Triplett is a brand of Jewell Instruments, based in Manchester, New Hampshire, which makes a diverse line of sensors and controls, meters, avionics and industrial test equipment including magnetic compasses and inertial measurement units with 3-axis magnetometers. For more info, see www.triplett.com and www.jewellinstruments.com.