Does a 100W lightbulb have a thicker filament or a thinner filament than a 25W bulb? It seems to me that since P = I^2R that one could either increase the current or increase the resistance. I would have thought thaat higher resistance would produce more light but I am not sure.
I ask this question because we use lightbulbs (with holes poked in the glass) to monitor oxygen levels in our inert atmosphere box. I have a chart that compares bulb life to oxygen levels for a 25watt bulb. I don’t know if a 25watt bulb would last longer or shorter than a 100 watt bulb.
Higher resistance would produce more light, except that higher resistance reduces the current flow given a fixed voltage source. I = V/R
Since the I in your power formula is squared, the net of it is that higher resistance produces less power. Think an open circuit (very high resistance) to a short circuit (very low resistance). The open circuit doesn’t do anything, the short circuit throws sparks, melts stuff and starts fires.
All I can say about the filaments is that the 100W will have a lower resistance filament than the 25W, but that could just as easily be a function of filament length as filament thickness.
Probably neither does anyone else who hasn’t run tests to find out.
A way to find out is to install a 100 W bulb in the chamber along with the 25 W for which you have data. If you intend to use a 100 W bulb you need to run a lot of tests in order to get data for a calibration curve that means anything at all.
From the ones I’ve busted open in the past as a curious kid, they have looked like identical filaments, but of either differing lengths, or doubled and tripled on the terminals.
I imagine it would greatly simplify manufacture to have a single gauge filament.