Oscillographs and their Tests
A. E. Kennelly, R. N. Hunter, A. A. Prior · Transactions of the American Institute of Electrical Engineers · 1920
A method and technique for the testing and calibration of oscillographs is described, using an auxiliary vibrator or ``oscillographmeter'' for the production of Lissajous optical figures, whereby the resonant frequency f0 of the tested oscillograph may be readily ascertained. From this and one other test, which is preferably a comparative calibration at 60 ~ and at the resonant frequeney, the bluntness of resonance B of the oscillograph is determined. From the two essential constants f0 and B of an oscillograph, its indications at any assigned frequency can be corrected for the inertia of its vibratory system. At high frequencies, the correction may be relatively large. A number of oscillographs have been tested for their f0 and B. The principal results obtained are reported in the paper.