how to do measure the temprature of a fire?

how to do measure the temprature of a fire?

 

The color can be an indication, because it tells you the temperature of a blackbody, though you have to be careful you don't have electron transitions giving you a different color from the emission spectrum lines. You could also use the flame to heat a solid and use that color as an indicator.

 

http://en.wikipedia.org/wiki/Flame#Flame_color

how to do measure the temprature of a fire?

 

Thermocouples placed in the flame work pretty well for moderate flame temperatures.

 

Pyrometers are used for higher temperatures, and as swansont notes, one can use spectrometry in some cases.

 

If you know the chemical species involved in combustion it is possible to calculate the adiabatic flame temperature using thermochemical computer codes. One can then also calculate the gas temperature at locations removed from the combustion site using thermodynamics and fluid dynamics. This is what is commonly done for rockets, where one has a combustion chamber that operates at high pressure followed by an expansion of the combustion gasses in a nozzle to generate high thrust.

Edited January 27, 201214 yr by DrRocket