VERFAHREN UND GERAET ZUR BESTIMMUNG VON WECHSELSPANNUNGS(AC)-KALIBRIERFEHLERN UND GERAET MIT EINER EINRICHTUNG ZUR LIEFERUNG VON WECHSELSPANNUNGS(AC)-KALIBRIERFEHLERN

摘要

Calibrating errors of a variable gain amplifier (12) used in an AC calibrator or AC meter are determined for a gamut of frequencies by adjusting a variable resistor (13, 14) in discrete steps and applying (16, 21, 27) a variable amplitude signal to the amplifier so that the amplifier produces a gamut of output signals of predetermined nominal values. These signals are detected (24, 23) and the actual values are compared (17) with the nominal values to derive a calibrating error for each resistor value. A gamut of variable frequency, constant amplitude signals is then applied (22, 27) to the amplifier while the gain is constant and the amplifier output for each frequency is compared with the output at a reference frequency at which the output is unaffected by reactive components in the circuit. The amplitude versus frequency response indication of the amplifier is then modified by the derived calibrating error signal. The calibrated amplifier is used in a voltmeter or AC calibrator so that the amplifier output is modified as a function of input frequency and gain setting. <IMAGE>