New Instrumentation of A-C Network Calculator with Automatic Features [includes discussion]
L. L. Fountain, R. B. Squires, W. A. Hopkins · Transactions of the American Institute of Electrical Engineers Part III Power Apparatus and Systems · 1953
Several improvements have recently been made to increase the operating speed and accuracy of the a-c network calculator. Load circuits are now set independently by using the portable load-setting console. New master instrument scales lead directly in system values. The greater sensitivity of the instrument amplifier makes it more accurate. The operator no longer has to select the correct range on the instruments because the automatic scale selector now does this for him, thereby allowing more time for interpretation of the board data.