The test measured advertised basic technical characteristics and other operational characteristics such as range, safety, compatibility between system components, and tamper resistance. All known manufacturers of EMD's were contacted, but only two companies submitted their systems for testing in 1985. The systems (transmitter and receiver/monitor) were tested in an open field, wooden residence, metal building, and a laboratory environment. Both systems performed as advertised with respect to operating frequency, operation range, and waterproof characteristics. Both systems have relatively low effective radiated output powers, making them susceptible to reduced operating range in the vicinity of certain configurations of metal objects and broadcast electromagnetic interference (EMI). They were not bothered by EMI from typical household products. Reduced operating range also resulted when the person wearing the transmitter shielded it from direct line of sight to the receiver/monitor. Neither system was unsafe and could transmit a signal different from that for normal operation. Two additional systems were tested in 1986, and results similar to the 1985 tests were obtained. 21 tables and 17 figures.