Hall Steel has three thermocouples measuring air temperature inside every furnace—"Air", "Over-Temp" & "Load".

The "Air" thermocouple measures the actual air temperature about half-way up on the side of the furnace box. The furnace cycle is set at various air temperature set points against this thermocouple.

The "Over-Temp" thermocouple is above the "Air" thermocouple on the side near the top of the furnace box. Since hot air rises, this thermocouple reads the air temperature where it is theoretically the hottest and automatically shuts down the furnace if there is a malfunction and the temperature rises above a pre-set temperature before it can damage (i.e. soften or melt) the items in the load or the furnace itself.

Thermocouple in the furnace load

"Load" thermocouple with test bars for ductile iron castings awaiting to be sub-critical annealed.

For our customers, the most important thermocouple is the "Load" thermocouple. This thermocouple is bolted between two blocks and is connected in series to the furnace controls and a chart recorder. These blocks simulate the inside of a steel plate or iron casting. For any furnace run, there is a lag in time (often hours) for the interior of a part to be at the same temperature as the outside (just like baking a cake or roasting a turkey in your home oven). By placing the thermocouple "in the load", Hall Steel is ensuring that the ENTIRE part is being stress relieved. Hall Steel is able to guarantee the soak time by holding the soak timer on the controls until the "load" temperature matches the "air" temperature.
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Hall Steel Corp
8050 North Granville Woods Road
Milwaukee, Wisconsin 53223 USA

Phone: 414-354-1020
Fax: 414-354-1021
E-mail: sales@hallsteelcorp.com
WWW: www.hallsteelcorp.com