1865 29 Apr. 280/3 The combination of a power meter..with an apparatus used to aerate and vaporize liquid hydro carbons.
1903 B. 6 66 Power Meter... This is an apparatus, patented by A. F. Nagle, for measuring the i.h.p., or rather the indicated work in a given time, at one end of an engine cylinder.
1992 23 311/2 Single element pyroelectrical detectors are widely used in spectroscopy, power meters and for intruder alarms.