Solar Manufacturing,Sellersville, PA, announced that it has received US Patent #11,815,403 for an innovative control thermocouple design for vacuum heat treating furnaces. This new thermocouple offers a significant advantage in controlling operating temperatures from ambient up to 1200°F (649°C), particularly in smaller diameter hot zones of 36 inches (91.44 cm) or less.
In conventional control thermocouple designs, the outer ceramic protection tube acts as a heat sink under these conditions. This thermal conduction, or heat loss, is compounded by the shorter length of the thermocouple assembly, causing it to operate at a lower temperature. As a result, the furnace’s heating elements increase power output to maintain the set-point temperature, leading to a hotter workload temperature than the furnace temperature. This issue is more pronounced at lower processing temperatures below 1200°F (649°C).
The newly patented thermocouple configuration addresses these undesirable thermal conduction losses. It has demonstrated improvements in temperature uniformity survey results. Meeting AMS 2750 standard temperature uniformity specifications requires control thermocouples to be properly located within the hot zone for accurate survey thermocouple measurements without correction factors.
