Today I am reviewing the MF100 AC/DC Magnetic Field Meter from Extech. The MF100’s primary function is to measure both AC and DC magnetic fields in gauss and mT (milli Tesla) via an advanced uniaxial Hall effect sensor with automatic temperature compensation. The Extech MF100 can be used in a wide variety of applications such as electric transmission equipment, power lines, microwave ovens, air conditioners, refrigerators, computer monitors, video/audio devices, particle accelerators, MRIs, industrial & research labs, transportation systems, elevators, battery power, wind power, etc.

The Extech MF100’s main unit fits into the user’s hand easily, while the other hand is able to freely move the probe around to measure for magnetic field. The unit features a power button, Hold button, Record button, Zero button, and “Mode DC/AC” to switch between DC and AC modes. The Extech MF100’s most notable features are its hall effect sensor with automatic temperature compensation, North pole & south pole indicator, Zero button for DC measurement, Data hold to freeze readings, MIN/MAX functions, and automatic shut-off when the unit has idled after a period of time.

The Extech MF100 comes with a convenient cover for the probe sensor when it is not in use, 9V battery so you can start measuring out of the box, and hard carrying case for safe storage and transportation. The unit only weighs 9.5 oz so it is not tiresome to use. Using the Extech MF100 is very easy and intuitive. Simply power it on, and move the probe towards the device or magnet you are measuring. The measurements are displayed in real time on the screen.

Have you ever been curious how much of a magnetic field your household electronic devices are emitting? Let us know in the comments!