Hadn't thought about that for a while but, now that you mention it, I think I remember the measurements changing with just a small change in the location of the phone. Regardless what happened to me, that's a pisser.From another experiment I ran yesterday I have no faith in these apps on my phone. I took it out in the sun and set the phone on the ground so it was always at the same angle etc. Set the light source for sunlight and the numbers were low so tried covering the sensor then exposing again and got totally different numbers every time. Same thing with the PPFD Meter app. I'm thinking my older Android 7.0 LG phone's sensor is not so good. I tried looking up which model of sensor it has but could not get any tech info which is what PPFD Meter wants to calibrate to my phone.
Just the fact the numbers bounce around so much it makes both apps useless to me. Pisses me off as I like free stuff.
One think that comes to mind. The app is "free" if you don't need to get the settings for a specific type of light. If you do that, it's just a lux meter and that's a different set of numbers. I think that you get one light type in the trial but I can't be sure — make sure to check what is says in the app.
Sorry if you can't get it to work out. It is a good value but if it doesn't work, it doesn't work.
Just checked Amazon and there are a couple of PAR meters that were "iffy" to me when I was shopping around but no longer. Back then, they were "unavailable" and the companies behind them were…not what I wanted to see. They were $300+ back then, too.I didn't bother ordering a light meter on amazon. Just got my milligram scale and some syringe filters.
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Now they're $150±. That's a steal. Just the wand for the Apogee is $60. I saw a posting on another thread/site that said that those light meters (they're the same sensor) were within 30 PPFD of an Apogee. In terms of accuracy, that's a huge value.
It's certainly not free but it can help put together the pieces of the puzzle.