Cartridge HeaterWatt-Flex® split-sheath cartridge heaters can be manufactured with a groove along the outside of the sheath to accommodate a needle-type thermocouple. This design provides more accurate sensing and control than those of conventional heaters for temperature-critical processing applications. The Watt-Flex thermocouple can be replaced independently of the heater and is movable, allowing temperature measurement at any point along the heater sheath. Split-sheath construction allows each half of the heater to expand independently when energized for exceptional metal-to-metal contact with surrounding bore. This in turn maximizes heat transfer even in oversized bores. Watt-Flex heaters are available in several diameters and lengths and with operating temperatures up to 1700°F.