Abstract: A vibration monitor is provided which is worn on the wrist of an operative for an operating plant or apparatus. The monitor includes a piezoelectric transducer and associated circuitry which generates electronic digital signals during the periods when vibrations are experienced by the operative. Preferably, the plant or apparatus has a transmitter which transmits a code identifying the plant which is received by the monitor. Alternatively, the code may be entered manually. The monitor preferably includes a logger which can be connected to a host computer which data can be transferred over an external communications link. The logger includes a storage device for storing how long the operative is subjected to vibrations.

Abstract: An acoustic temperature measurement system for pipeline fluids comprises a loudspeaker (16) with spaced microphone (18) in a sealed pipe (10) with end cap (11). A computer arrangement (22) provides a tone burst signal which drives the speaker via power amplifier (21) and the outgoing and reflected signal is detected by the microphone (18) and following amplification in amplifier (20) passes to the computer (22) for processing. The signals are processed to determine phase relationships indicative of temperature and can be used in correcting leakage measurement readings.