NASA - Stennis Space Center, United States
pp. 319 - 322
Keywords: wireless, one-way, sensor, asynchronous, piezoelectric, explosive
The technology developed is a monitoring system that includes a base station and at least one sensor unit mounted at some distance away, which is in wireless, one-way communication with the base station. The sensor lies dormant until it receives a voltage trigger from a vibration-sensitive switch which consumes no stored power from the battery. When activated, the sensor takes a measurement, transmits the data to the base station, and then returns to its dormant state. The measurement taken is recorded and time stamped. The system can be utilized in commercial applications that require long term monitoring of events associated with different types of strain, cryogenic temperatures, ambient temperatures, limit switches, 4-20 milliamp signals, 0-10 volt signals and magnetic fields. Though designed to improve the monitoring of high-geared and linearly-actuated ball valves used in rocket propulsion testing to more accurately predict valve life span and premature failure, its use is not limited to valves, and can be used to monitor the operational data of any suitable structure, such as the temperature in a particular location in a building, or the strain at a specific point on a bridge.