- #1
lucas_
- 413
- 23
Please confirm my understanding and inquiry..
in material without transmission... 100% = Emissivity + Reflectivity...
when using thermal camera (I own one).. we have to adjust the emissivity
In two objects that is both 30 Celsius.. one a near black object with emissivity nearly 1 (black body) and another a reflective aluminum. We know the aluminum reflects more hence the thermal camera would see less heat if emissivity not adjusted in the camera.
my inquiry. even if the reflective aluminum has less emissivity.. it is both 30 Celsius as a near black object beside it. Does it mean the molecules vibration inside both are hiding same black body spectrum? with the reflective object not emitting it outside? I mean.. I know the atoms vibrate at IR range and it is producing the frequency producing the heat.. so one atom vibrates at certain frequency producing certain photons.. and different atoms vibrating at different frequency producing certain photons? Or do the atoms vibrate and redistribute the frequencies via normal modes? If so how come reflective aluminum has less emissivity.. meaning it radiates less frequencies? Are the frequencies just hidden inside the atoms due to the fact that reflective object reflects the IR from the surrounding. I mention hidden because the reflective object and black object are both 30 Celsius even if one has less emissivity (in other words, what goes on internally in the molecules of objects.. one with less emissivity versus one with more.. yet both having same temperature.. why are they still same temperature if the IR radiation is responsible for the temperation.. unless the conduction, convection can still produce the black body spectrum that hidden inside both materials explaining why they are same temperature?).. are my questions clear.. i'll rephrase if no one still understands what I'm asking or saying).. thank you..
in material without transmission... 100% = Emissivity + Reflectivity...
when using thermal camera (I own one).. we have to adjust the emissivity
In two objects that is both 30 Celsius.. one a near black object with emissivity nearly 1 (black body) and another a reflective aluminum. We know the aluminum reflects more hence the thermal camera would see less heat if emissivity not adjusted in the camera.
my inquiry. even if the reflective aluminum has less emissivity.. it is both 30 Celsius as a near black object beside it. Does it mean the molecules vibration inside both are hiding same black body spectrum? with the reflective object not emitting it outside? I mean.. I know the atoms vibrate at IR range and it is producing the frequency producing the heat.. so one atom vibrates at certain frequency producing certain photons.. and different atoms vibrating at different frequency producing certain photons? Or do the atoms vibrate and redistribute the frequencies via normal modes? If so how come reflective aluminum has less emissivity.. meaning it radiates less frequencies? Are the frequencies just hidden inside the atoms due to the fact that reflective object reflects the IR from the surrounding. I mention hidden because the reflective object and black object are both 30 Celsius even if one has less emissivity (in other words, what goes on internally in the molecules of objects.. one with less emissivity versus one with more.. yet both having same temperature.. why are they still same temperature if the IR radiation is responsible for the temperation.. unless the conduction, convection can still produce the black body spectrum that hidden inside both materials explaining why they are same temperature?).. are my questions clear.. i'll rephrase if no one still understands what I'm asking or saying).. thank you..