The Echo wireless vibration monitoring system from IMI Sensors, PCB Piezotronics Inc., Depew, NY, uses wireless sensors to transmit overall vibration levels, scaled in acceleration and vibration, as well as crest factor. The system uses ultra-narrow-bandwidth RF communication and extended-range RF (ERRF) technologies operating in the 902–928 MHz unlicensed ISM band with a –155 dBm noise floor and -145 dBm sensitivity, and outdoor transmission distances to 1.5 miles and an 1800 ft. radius in a typical plant environment using a single receiver. The system includes standalone, battery-powered Model 670A01 wireless vibration sensors, the Model 672A01 8-channel wireless junction box that converts installed industrial sensors to wireless operation and transmits the measurements wirelessly, and the Model 673A01 wireless receiver.