Citizens are often afraid of electromagnetic fields. This creates a need for logging and quantifying the exposure to fields in the civil environment. An electromagnetic field strength sensor (from 1MHz to 1GHz) has been developed which is connected to a logging system and a modem. The systems output level is independent of frequencies i.e. follows the standards limit curve. It can be powered by solar cells. So it can operate without human interaction anywhere. The system can emit a warning when the exposure level is exceeded. In normal mode, it transmits the logged levels once per week to a central data collection system.This paper describes the design and operation of the system.