The listed range of our thermocouple is -200 to 1400 Celsius. The Flinn catalog (p 205 of 2004 edition) lists temperatures up to about 1600 C. These temperatures are, we think, measured optically.
In our tests with our thermocouple in bunsen burners, the tempeature measured did not get above 1400 degrees C. We think what happens is that the metal of the thermocouple acts as a heat sink to the extent that you do not get temperatures above 1400 degrees. It may also be that the temperatures listed in the Flinn diagram are for the very best bunsen burner at optimum conditions.
We do not think it is possible to damage the tip of our thermocouple in a bunsen burner flame and studying the flame with our thermocouple is a great way of demonstrating the differences in temperatures at different locations in the flame. It is also very interesting to compare the temperature of different types of flames, candles, alcohol burners, etc.