Thermal gradient furnace

Archaeological Ceramic Study Possibilities with a Thermal Gradient Furnace... 

Recently it was possible to construct for archaeological studies a thermal gradient furnace similar to one used in the ceramic laboratories of the College of the Earth and Mineral Sciences of The Pennsylvania State University. Robert Frantz modified the design of the earlier furnace so that it would be suitable for testing archaeological clays and sherds that are available only in small quantities. 

Figure 2. Thermal gradient furnace with control panel...

Figure 3. Thermal gradient furnace showing thermocouple distribution...

Figure 5. A time-temperature firing schedule of the thermal gradient furnace at the 12 thermocouple points of measurement...

The furnace is a Marshall high-temperature testing furnacet (d), with nine zones. Shunt resistances are placed selectively across the winding of the furnace to establish a thermal gradient across the 4-in. length of the boat, with the V-shaped end of the boat at the cool end of the gradient. A Pt—Pt— 10%Rh thermocouple is used... 

During the tests, the stack and SRU were instrumented to record voltage on each cell and to measure temperatures at different positions to highlight thermal gradients if present. Mechanical load was applied through weights external to the furnace. The load level was adapted to the stack/SRU design. 

TG, a null-point mechanism is to be preferred, as this ensures that the sample remains in the same part of the furnace, even when the mass changes. Thus any effects due to thermal gradients within the furnace tube remain constant. 

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