A TDM wattmeter with a 0.5-MHz carrier frequency

The author describes a standard time-division-multiplexing (TDM) wattmeter with a constant average carrier frequency, no inherent phase error, and known systematic magnitude frequency error, as well as efforts to increase frequency bandwidth. The residual error of the wattmeter, after corrections, is below 100 p.p.m. up to 5 kHz. The meter is expected to find application in accurate power measurements under distorted and low power factor conditions, and as a transfer standard for interlaboratory comparisons.>