Extreme High-Temp Furnace Profiling for Heat Treating

Process- and quality-control monitoring must be done even in the most extreme conditions, such as in heating and soaking furnaces for forging billets, or in heat-treating or curing furnaces. In an example of the latter, CAS DataLoggers — developers of standalone data logging, data acquisition, and temperature monitoring devices —  provided an oven-temperature profiling package for a manufacturer that aimed to monitor its heat-treating line. This process involves large batches of alloyed materials exposed to high temperatures through a long curing process.

The customer’s large production runs are treated in batches over several hours in three large ovens running continuously. To ensure consistent product quality, it was especially important to have proof that the material had passed through the manufacturing process at the right temperatures, for the right amount of time. Any data logger solution would need to connect to Type K thermocouples and — given the ovens’ 800°F (426°C) temperatures — the customer also needed an especially resilient thermal barrier. Not incidentally, all these factors had to be addressed within a fairly strict budget.

CAS DataLoggers supplied the customer with a Grant portable oven temperature data logger that offers six thermocouple input channels for use with Type T and Type K thermocouple probes, and supports fast sample rates that make it possible to collect multiple samples at high speeds — up to eight samples per second.

The heat treater also opted to equip the data logger with a custom enhanced thermal barrier, with an internal heat sink that is capable of advanced phase-change technology, for maximum protection and heat absorption. The barrier’s all stainless-steel construction forms a robust and protective barrier for the data logger.

The standalone oven temperature profiling data logger is battery-operated and easily portable, so it forms part of a complete system for the through process-monitoring.

Users navigate the logger’s menus through the simple, three-button design via the built-in display and also navigate these functions from a PC. Configuration makes it possible for the data logger to automatically start and stop recording at specific times, and to determine temperature levels, to give users the most accurate process overview. Each reading reports the time and date, while the logger’s non-volatile memory provides up to 260,000 readings of secure data.

By passing the Grant oven logger through the process along with the products, a temperature profile was produced to show exactly what was happening to the products being heat-treated during the process cycle. At the end of a production run, the logger automatically delivers a percentage cure result on its integral screen. A quick unload of the data via the integral USB port allows further analysis, reporting, and data archival.

The custom thermal-barrier’s phase-change insert and heat sink endured to the extreme heat of the treatment cycle, ensuring the reliability of the logger.

The manufacturer’s treated products have exhibited improved quality following use of the Grant oven logger in their heat-treating application. Additional benefits include increased efficiency, reduced energy costs, quality assurance reports for compliance and traceability, and complete quality control for the process. Also, the thermal barrier’s solid construction offered excellent protection for a comparable price to others on the market.