Aluminum Wire
The Aluminum wire diameter is less than the pyrometer measurement spot, and using a smaller spot is not feasible because the wire will shift out of the field of view.
If the wire is smaller than the spot, effective emissivity will be the function of the ratio of square:
Square of the wire/Square of the spot
- a) when spot Ø10mm, and wire Ø2mm, effective ε=0.25; Real wire surface ε=0.1;
and full measurement emissivity will be E=0.025;
- b) When spot Ø10mm, and wire Ø6mm, effective ε=o.75 ; Real wire surface ε=0.1
and full measurement emissivity will be E=0.075”
It is evident that the pyrometer emissivity settings need to be adjusted for each wire diameter.
Consider a pyrometer that has a manufacturer-specified minimum brightness temperature of 105C degrees.
If E=0.025, then minimum the temperature will be=210C If E=0.075, then minimum the temperature will be=170C
The measurements may also be affected if the wires are made of different alloys.
The situation is likely to be simplest in this case:
-A customer consistently uses the same alloy.
-The customer will utilize a fixation wheel to prevent wire movement, ensuring that the measurement spot remains stable. Consequently, the spot diameter can be less than 10mm.