I’m looking into getting a affordable par meter. I’ve used a dr meter “Lux” meter in the past to try and get into the ball park but that method seems to leave me guessing too much and I either burn the plants or give them too little. I do have a newer samsung android phone so I downloaded a few apps " photone & PPFD meter" I used the handheld LUX meter I have and calibrated both apps, they both say different things regarding par/ppfd but agree on lux with the real lux meter. PPFD meter app seems to be the closest match to what the charts say LUX to par is suppose to be …ball park.
Both apps report lux readings and follow the real meters readings just fine after I calibrated them. It’s the par / ppfd readings that are so different.
For example:
Dr meter real lux meter, says lux is 22000. *
Lights are bridgelux 3500k leds *
PPFD app on phone says lux is 22000 and ppfd is 330. * I set the light src in the app to 3500K
photone app on phone says lux is 22000 but ppfd is 550. * does not have k values so the closest was full spectrum to select light src.
This one not so sure about but does have a lot of features. It’s more than I really wanted to spend but thought I’d ask anyways to see if you guys use them.
The uni-t looks like it does the same thing I already have and used to calibrate both apps. Is there something different about uni-t than this one…doesn’t seem so.
@DougDawson Same exact one I use! Going on 3 years now no issues. I’ve reached out to the company as well before asking about the screw in spot in the back and not being able to find sticks to hold it they said most selfie sticks and certain camera tripods will work for it. @Taproot this a great product although it’s getting close to the $200 mark now
I see that yours is Bluetooth so you can pair it with the ppfd app, I assumed it was just for the initial calibration but it seems to use that cheap lux meter as the sensor instead of the phones. My lux meter isn’t Bluetooth but I’m able to input the data into the ppfd app and calibrate them to match and they continue to be fairly close moving them around. My phone has a ALS sensor so it doesn’t use the camera. I’m curious if others calibrated ppfd this way…but what’s interesting is the difference between photone and ppfd of which both have been calibrated by the same lux meter and match it pretty close but have a gap in the par readings. Perhaps because photone uses the camera and ppfd uses the built in light sensor. Regardless can these apps see the UV and IR like a normal par meter? I will say I like the apps because it calculates the dei and can generate par maps.
You’re a little over my pay grade with this discussion I’m afraid. I got the uni-t because my phone didn’t have the right type of sensor in the camera to use the ppfd app.
I heard about it on the migro yt channel. He worked with ppfd meter app people to develop the app I think.
The only thing I don’t like about the apps even when paired with a Uni-t is they can’t see the UV / IR / deep reds. The app uses a coefficient when you tell it you have 10% reds etc to approximate. It does seem ppfd gets real close. Does the photobio see all the spectrum…looks like it can see 400 - 700nm?
Hopefully the app devs can work with somebody to get a sensor that is capable of seeing a broad spectrum in a simple and cheap package like the Uni-T so we can just pair it up and have a really nice and capable meter. That should allow the apps to double as a spectrum analyzer.
