The ZUMBACH AUTAC 300 is a non-contact digital temperature controller designed for wire and cable extrusion lines. It measures conductor temperature using the convective heat flow principle—sensing the thermal boundary layer around a moving wire without physical contact—and is therefore independent of the wire's color, surface emissivity, material composition, and line speed. The measurement head accommodates wire diameters from 0.2 mm to 7 mm with ceramic guides and an optional slotted head that allows threading without cutting the wire. It operates reliably at line speeds up to 1,500 m/min, with an optional upgrade to 2,500 m/min for high-speed extrusion lines.

How does the AUTAC 300 control wire preheating?

In a cable extrusion line, the conductor must be preheated to a specific temperature before it enters the extruder crosshead—too cold and the insulation does not bond properly to the conductor; too hot and the conductor oxidizes or the insulation degrades. The AUTAC 300 measures the wire temperature immediately upstream of the extruder and, in its preheater-integrated version, closes the control loop by adjusting the preheater output power to maintain a user-defined setpoint. The stand-alone version outputs the measured temperature as an analog signal (0–20 mA or 0–10 V) or via RS-422/Ethernet to a host PLC or preheater controller. Both versions can operate as a temperature limiter—triggering an alarm or stopping the line if the wire exceeds a maximum threshold, protecting the insulation material from thermal damage.

What makes convective heat flow measurement different from infrared?

Infrared (IR) temperature sensors measure surface radiation and are sensitive to the target's emissivity—a bare copper wire, a tinned conductor, and an oxidized aluminium strand all radiate differently at the same temperature, requiring emissivity compensation. The AUTAC 300's convective heat flow principle measures the thermal energy carried from the wire surface into a controlled air gap within the measuring head. Because convective transfer depends on the temperature difference between the wire and the sensor, not on radiative properties, the reading remains accurate regardless of the wire's material, color, or surface condition. The measurement is also insensitive to ambient temperature fluctuations and air currents in the production environment, making it suitable for unheated factory floors as well as temperature-controlled extrusion halls.