Abstract: A wireless monitoring unit performs condition monitoring associated with a test point location of a host machine. The unit includes a high performance vibration sensor useful for monitoring the host machine for fault conditions and the like. The unit includes a second vibration sensor that has poorer metrological performance, but draws a comparatively insignificant amount of power from the battery. The second sensor takes a vibration measure periodically, which measure is processed to evaluate whether the machine is in a state eligible to undergo a health assessment. Diagnostic monitoring using the high performance vibration sensor is enabled only when the host machine it is in the eligible state. A low power temperature sensor provides additional data for guarding against a false trigger, in effect allowing the processor to distinguish against vibration from another machine propagating to the host machine causing the host machine to vibrate while the host machine is not running.