EMF Meters Information

EMF meters detect and monitor harmful electric, magnetic or electromagnetic fields surrounding personal or work areas. Electromagnetic fields (EMF) are invisible lines of force produced by the voltage and current which surround electrical wires or devices. These physical fields consist of two components: the electric field, which is the result of the voltage; and the magnetic field, which is the result of the current flow. One of the most common places for EMFs is near power lines; however, EMFs may also occur near electrical appliances and office equipment. In terms of human health and safety, some research indicates that elevated levels of extremely low-frequency (ELF) EMFs may cause cancer and leukemia. Consequently, electrical workers and other maintenance personnel may use EMF meters before entering a job site.

EMF meters can combine magnetic, electric and radio frequency (RF) or microwave detection in a single package. Handheld devices vary in terms of measurement speed and cost, but are reliable instruments for detecting electromagnetic pollution. Specifications for EMF meters include measurement range, frequency bandwidth, percent accuracy, sampling rate, minimum resolution, number of axes, weight, dimensions, power requirements, and operating temperature. There are two measurement ranges for EMF meters: milliGaus (mG) and micro Tesla (microT). Most Gaussmeters have a measuring of range of 0.1 to 199.9 mG . Most Tesla meters have a range of 0.01 to 19.99 microT. Choices for frequency bandwidth include 30 to 300 Hz, 1 to 200 kHz, and 11 Hz at 3 db. Typically, percent accuracy is measured at 50/60 Hz.

EMF meters vary in terms of features and applications. Some products have audible, adjustable alarms that sound when an electromagnetic field is encountered. Others provide datalogging capabilities with a date/time stamp for field use. Devices that have an RS-232 or universal serial bus (USB) interface are also commonly available. In terms of applications, EMF meters can be used to identify AC magnetic fields, AC electric fields, and RF radiation. Specialized EMF meters can detect hidden sources of extremely low-frequency (ELF) radiation from computers, kitchen appliances, television sets, vacuum cleaners, electric can openers, hair dryers, and power tools. Magnetometers are used to measure the direction and/or intensity of magnetic fields.