Back to your search result

Description

The most accurate ac voltage measurements are made by comparing the heating effect of an unknown ac signal to that of a dc reference using devices known as thermal converters. In its most basic form, thermal converters consist of a thermocouple placed at the midpoint of a heater structure, commonly a thin wire. These devices are extremely broadband, with a frequency range from 10 Hz to more than 100 MHz, and generally have input voltages limited to a few volts. The quantity of interest, called the ac-dc difference, can be nearly zero at audio frequency, but may be as large as several percent at 100 MHz.