The GQ EMF-390 advanced multi-function digital EMF ELF meter is designed and developed by GQ Electronics, Seattle, USA. It is a portable and convenient device. It can be used in general purpose test, detection and other scientific applications. Such as Power Line, WiFi, Cell phone, Cell tower, Microwave, Smart Meter, etc. The device integrated features include three axis Electromagnetic Fields, Electric Field, Radio Frequency and Radio Spectrum Power Analyzer. The meter is able to identify/recognize the common source from EMF/RF measured, such as Power Line, WiFi/Cell phone, Cell tower, Microwave etc. It also comes with built-in audible and visual alarm. It can be used for EMF, ELF, EF, RF detection and monitoring both indoor and outdoor, as well as in other similar environments. The EMF-390 has built-in flash memory for data logging, it can log the real-time data every second with timestamp. The history data can be be downloaded when the device linked to a PC.