Finding the temperature of light bulb filament?

In summary, the student is conducting an independent study project on resistance vs. temperature in non-ohmic material and is trying to find the temperature of the filament using surface temperature measurements. However, this is difficult without an optical pyrometer, which measures the color of the filament to determine its temperature. Researching color/temperature charts and using a standard photovoltaic cell may help in determining relative temperatures, but further guidance may be needed for practical application.
  • #1
teatime
2
0
So for my physics independent study project. I am studying the resistance vs. temperature in non-ohmic material. I passed different currents through the light bulb and took the surface temperature with a thermocouple. How can I find the temperature of filament using the surface temperature measurement? My teacher seemed to think that would be easy, but I can't find it anywhere. Can anyone please help me? I do not want to start my project all over again and I don't know how I would even measure the temperature of the filament seeing as my school does not own a optical pyrometer.

Thanks.
 
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  • #2
The filament temperature will be hard to get given only bulb surface temperature measurements. However, the color of the filament is a direct indication of the temperature. Devices called optical pyrometers are used to take this type of measurement. Do some research in that direction, perhaps you can find color/temperature charts which will be useful.
 
  • #3
The intensity of the radiation from a blackbody is proportional to the forth power of the BB temperature. You can determine relative temperatures by a standard photovoltaic cell's measurements of the emitted electromagnetic energy.

Mine is a simplification of the process you seek. Integral knows better what to do in practice, however.
 

1. How is the temperature of a light bulb filament measured?

The temperature of a light bulb filament is measured using a device called a pyrometer. This device uses infrared radiation to measure the temperature of objects, including the filament of a light bulb.

2. Is the temperature of a light bulb filament the same as the brightness of the bulb?

No, the temperature of a light bulb filament and the brightness of the bulb are two different things. The temperature of the filament determines the color of the light emitted, while the brightness is affected by the voltage and current running through the bulb.

3. What factors affect the temperature of a light bulb filament?

The temperature of a light bulb filament is affected by several factors, including the amount of current running through the bulb, the type of gas in the bulb, and the type of material used for the filament. The higher the current and the lower the gas pressure, the higher the temperature of the filament.

4. Can the temperature of a light bulb filament change over time?

Yes, the temperature of a light bulb filament can change over time. As the filament ages, it may become more resistant to the flow of electricity, causing it to heat up more and increase the temperature. This can also lead to a decrease in the brightness of the bulb.

5. Is there a maximum temperature that a light bulb filament can reach?

Yes, there is a maximum temperature that a light bulb filament can reach. This temperature is determined by the melting point of the material used for the filament. If the filament reaches this temperature, it will melt and the bulb will no longer work.

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