Fluke Corporation

Jiajun Yan

Tian Xia

Richard W Walker

The core of a high temperature furnace has an elongated central test cavity for testing/calibration of a temperature-sensitive component, such as the probe of a thermocouple. At least three electrical heating elements as positioned adjacent to the test cavity, including two elements adjacent to the opposite end portions of the test cavity, respectively, and a center element between the end elements. A uniform temperature profile is maintained in the cavity by control circuitry that manages the supply of electrical power to the heating elements, by periodically configuring interconnections of the elements during multiple phases of a duty cycle. The duty cycle includes a first phase in which current is passed through the center element, a second phase in which current is passed through the end elements in series, and a third phase in which current is passed through one of the end elements and also through the center element without passing current through the other end element.

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Shanghai, China

Jiajun Yan