A multiplier based on thermal converters was developed for use in broadband power measurements. The topology of the multiplier suppresses its static error by means of an improved summing circuit. It employs a fast synchronous ac-dc transfer technique to shorten the measurement time. The uncertainties evaluated at the nominal voltage of 3 V are on the order of a few parts in 10 -6  for frequencies up to 30 kHz and a few parts in 10 -5  for frequencies up to 100 kHz.
['Enrico Mohns']
An audio frequency multiplier with planar thermal converters for power measurements