Fluke Process Instruments Debuts Thermal Measurement Solutions for Harsh Environments

October 05, 2021 by Seth Price

What is this new furnace tracking system and why is it important to monitor temperatures in these extremely hot environments?

Industrial furnaces and ovens are very commonly found in harsh environments where heat treating in metallurgy occurs. These devices are often used in metallurgical production for heat treatment, tempering, drying, and fermentation at lower temperatures. 

Fluke has released a new data logger for determining the thermal profile inside furnaces and ovens. The Fluke Datapaq Furnace Tracker system can take data from 10-20 thermocouples and log the temperatures through a cross-section of the furnace. 


Video used courtesy of Fluke Process Instruments


These thermal profile devices can track how evenly items are heated in a furnace, increasing uniformity in heat treatments. It also allows engineers and technicians the data to determine when to perform furnace maintenance.


Heat Treating in Metallurgy

Several metallurgical processes such as annealing, precipitation hardening, carburizing, and others require reheating material to enhance physical properties. 

Annealing requires metal parts to be heated to around ⅓ of their melting temperature to relieve residual stresses. Forming operations performed below ⅓ of the melting temperature (cold work) hardens the part and reduces the fracture toughness. 

To relieve these stresses, the material can be heated after processing, or in the processing can be performed above ⅓ of the melting temperature (hot work), either of which will relieve stresses from processing.


Parts being loaded into a heat-treating furnace. Image used courtesy of Fluke Process Instruments


Precipitation hardening is performed by heating certain alloys (some aluminum, titanium, and magnesium alloys) to increase their yield strength. 

Carburizing is a process where steel is heated and then exposed to carbon monoxide (CO) gas. The carbon atoms diffuse into the surface of the steel, increasing its hardness and wear resistance. Because diffusion rates increase with increased temperature, this process is performed under high temperatures. Gears, ways, guide rails, and other high-wear surfaces are often carburized. This task is often referred to as case hardening.


Datapaq Furnace Tracker

The Fluke Datapaq Furnace Tracker can record temperatures from up to 20 thermocouples at a time. The system can measure temperatures through a cross-section of the furnace, whether the furnace needs to be uniform throughout or whether the furnace has several heating zones at different temperatures. 

Users can communicate to the tracker and the computer via Bluetooth or USB, which allows for wireless or cabled connections. This communication feature may be especially useful for inductively heated furnaces. 

These furnaces can generate additional radio frequency (RF) interference. Once the data is in the computer, there are three software options: a graphical user interface (GUI), and software wizards, and help screens so that engineers can properly analyze the data. 


Surviving Harsh Environments

The Fluke data acquisition system is capable of surviving temperatures up to 800 °C (1472 °F). This system comes with additional hardware such as more unique thermocouples and a floating plate thermal barrier to allow temperature measurements up to 1050 °C (1922 °F). Other optional models are suitable for vacuum heating systems as well.


The complete Datapaq Furnace Tracker system, hardware, and software. Image used courtesy of Fluke Process Instruments


The two case designs are waterproof to IP67 standards, meaning they are safe from water spray in quenching stages. Engineers can use the same data acquisition system to measure the temperature through all of the hot furnace stages and the water quenching stage.

The Fluke Datapaq Furnace Tracker system can also determine whether a furnace is heating evenly or whether it needs refractory brick replacements or a damaged burner needs to be repaired. It can also ensure that furnace heating and quenching stages perform as expected, all from the same system. 

Fluke is hopeful that this new system can help engineers more accurately measure and record data in these extremely hot environments.