Dalton commonly supplies heaters with a side groove along the split profile to accommodate the use of a thermocouple for temperature monitoring. Larger heaters present a problem for grooving along the side during the heater swaging process, so ½” and longer heaters will receive a center groove. This is an .040” (1mm) diameter groove worked into the heater legs down the center of the heater, generally up to about 20” long.
The thermocouple, which measures resistance change about 1/8” from its tip can be inserted to any specified depth. The resistance change is converted to a change in temperature by a controller. We are often asked what the best positioning of the t/c with respect to its ability to accurately indicate temperature.
The groove will always be extended well into the heated section and past any cold terminal end … it is often extended to the middle of the heated length, but the even temperature profile of the Watt-Flex® cartridge heater allows effective monitoring at any point in the heated section. The t/c can be inserted to the point that it bottoms out in the bore to allow for maximized heat transfer/monitoring.