Measuring PAR / LUX

[ak-51]

I have been interested recently in getting a PAR meter to track the degradation of my bulbs over time. I was poking around and it seems that quality PAR meters are in the $300+ range. Is a meter to measure the light from my bulbs worth the cost of 3 new bulbs right now? No.

Would a cheap (<$50) LUX meter work for just measuring percent degradation? Or would LUX and PAR degrade at too different of rates to be accurate?

My main goal here is to identify the ideal time to replace my bulbs.

I was also thinking that I might run my bulbs at 100% until they degrade to x% and then turn on the Super Lumens to squeeze the last bit of life out of them.

 

[mean mr.mustard]

I think if you use a LUX meter to find when you drop 10% in light intensity it would work just fine... but I don't know whether or not either meter would register the same degree of difference.

I believe PAR meters grab the entire spectrum from 400 to 700 nm and LUX meters grab mostly the green yellows that plants don't use.

I have read that both seem to be measuring in the same difference with different values, which would make sense because I would think that the bulb would be emitting the same spectrum just at a lower intensity.