PAR meters tested. $8 iPhone app, $170 and $500 meter

iggy097

Well-Known Member
For anyone that was following. Here are the results from the $8 iPhone app - Photone (led mode purchase - iPhone pro 14 - diffuser) - a $170 PAR meter and the $500 Apogee meter. The iPhone app is way high. Mid priced meter is very close to the high end.
 

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bubba73

Well-Known Member
For anyone that was following. Here are the results from the $8 iPhone app - Photone (led mode purchase - iPhone pro 14 - diffuser) - a $170 PAR meter and the $500 Apogee meter. The iPhone app is way high. Mid priced meter is very close to the high end.
Seen where they put a piece of white paper around the camera , maybe that will help with the high # … great write up.
 

groworm

Active Member
did you use the exact weight of paper that they specified (22lb iirc), and did you try a calibration? the ratio of the high and low readings looks to be within ~5%, so might have some use as long as you could have confidence that the initial reading/calibration was accurate..
 

VincenzioVonHook

Well-Known Member
i found a lux meter with the results multiplied by 0.017 to be within a few percent of a good PAR meter if you have an average spectrum (3000k/5000k for example with a few 660's). Im at 37500lux which multiplied by 0.017 equals 637umol/s. The apogee I rent from a lighting shop reads 668umol/s. Thats accurate enough for me to get a hold of intensity.

I'm pretty sure it was Dr Bruce Bugbee and Shane from Migro who put me onto this equation. I gave up using phone apps when the apps were telling me my 240w quantum board puts out just over a third of the PAR that my shitty 240W blurple I have here put out, even with the spectrums set. It reckoned the 120x10w LED purple was putting out 1870umol/s at 18", and it read the 436 diode LM301B board with meanwell driver at 643umol/s at the same distance. Both are very wrong.
 
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iggy097

Well-Known Member
did you use the exact weight of paper that they specified (22lb iirc), and did you try a calibration? the ratio of the high and low readings looks to be within ~5%, so might have some use as long as you could have confidence that the initial reading/calibration was accurate..
They called for 20# paper at 92 White. The copy paper I had was 20# at 96 White. So - that being said, nobody is going to have the exact paper these guys want you to get from wallmart. They are going to have regular paper, or envelopes, or mail or something.
 

weednerd.anthony.850

Well-Known Member
I currently use the Photone app with good results with the little paper diffuser on my iPhone

I wish I had a proper meter but I’ll probably budget that in soon after the next few grows
 

iggy097

Well-Known Member
I originally did this comparison with standard copy paper - which is 22# weight. After posting my results on Reddit, a developer asked me to try some different paper. What I learned - if you are going to use this app to measure PAR - it seems to be very accurate - even compared to the high end Apogee. HOWEVER - the developers should/need to mention that in order to get accurate results you MUST use 22# paper, which is not standard copy paper.
The instructions in the app say "Use regular matte white printer paper (22lb or 80g/m2) - 22lb paper is not the standard paper, and most users are most likely not going to have it readily available.

Video if anyone is interested -
 

pahpah-cee

Well-Known Member
If someone were to have access to a bunch of those photo bio meters- where could one (theoretically) unload them at? I know RIU is off limits.
 
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