An Electrodynamic Ammeter for Use at Frequencies from One to One Hundred Megacyles

Although thermoammeters are used universally for measuring current at high frequencies, there has been until recently no independent method of checking their accuracy. The electrodynamic ammeter was developed to meet this need by providing a standard, based on an entirely different principle of operation. It gives an absolute method for the measurement of current at frequencies above a megacycle. A description and theory of the instrument is presented.