A small compact device capable of indicating the presence of microwave radiation and radio emissions from unsuppressed motors etc.
The initial ‘handshaking’ signal from a mobile phone will turn an LED on for a few seconds if the device is in close proximity to a mobile phone (i.e., it signals just before the phone rings or when it is switched on). The indicator will also signal if placed in close proximity to a microwave oven door. (Note: This is not a quantitative device but was developed as part of an environmental awareness pack. It can, however, illustrate how certain types of shield prevent the passage of microwave radiation.)