High Temperature Furnaces
The FTA long range microscope kit can be used with commercial tube furnaces for measurements as high a 1800C. Tube furnaces are preferred to other types because one end of the tube can be left open with little effect on the termperature in the center working zone, and the end of the tube is at a cooler reasonable temperature so you can fit a simple window if needed. The long range microscope can then view the sample through this open end.
At temperatures in the 900C and above range, the sample will glow enough that it does not need to be backlit like an ordinary room temperature measurement. At lower temperatures a back light can be fitted to the other end of the tube.
A good choice for most purposes is the Lindberg/Blue M single zone 1500C tube furnace. This can be purchased through many distributors, of which VWR is one. Their current catalog number and link (which could change in the future) is 30760-084. The price at the time of this writing was $6140 in the US. This price included the controller. Higher temperature furnaces cost considerably more, so you only buy what you need.