A Wattmeter for Communication Circuits
Kenneth R. Eldredge · Transactions of the American Institute of Electrical Engineers · 1935
An attempt has been made to devise a different type of wattmeter for measuring power and power factor in a-c circuits such as those found in communication service. An adjustable network has been constructed in such a manner that when it is balanced in 3 operations the power factor is indicated directly and the power can be obtained by a short and simple sliderule calculation.