Was your cheap meter a LUX meter? I know they have issues with LED’s
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I did like the Pulse Pro and all the extra features. Looks like a super cool unit that brings an abundance of stuff to the table.
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I think it was. It’s been quite a while. It had problems with HID’s as well.
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I don’t think the 700-730 is a big difference, but I don’t know why it wouldn’t be included? So apogee says 400-700 in the short description, but then when you look at specs it’s a little different. I don’t see actual technical specs on the other one. I would want to make sure it is actually 400-700. Tolerances are better on the apogee, but again I think it comes down to budget from what I can see. Hopefully someone with more experience with these will chime in.
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I’m pretty sure they have an extended range sensor for the far red/IR spectrum.
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Apogee, Li-cor, et al are more or less the industry standard for scientific measurement. Next step up is the utilization of spectrophotometers and integration spheres which only gets exponentially more expensive.
If you are writing a paper for publication, want to asses many light sources, or want to eek out higher accuracy, the scientific grade instruments are what you’ll opt for. Or, if you need something that you use all-of-the time / everyday … better tools and all that.
The inexpensive meters are likely perfectly fine for what most need them for and are likely accurate enough even if it’s more or less for relative measurements. For our general purposes, it’s mostly hand grenades. Yea, it’s ~700 PPF vs ~600 PPF, more than good enough to dial things in. And, these things will probably keep getting better over time too though there are physical (as in physics) limitations.
FWIW, Apogee has a whole line of sensors with varying spectral response including extended PAR that go well in FR and/or UV. Yes, they are not inexpensive.
Also to note, there’s more to it than just be able to read the photons. Incident angle of the photon to the sensor face impacts the result. It’s why you see some of the sensor accessories include a leveling plate. The higher end sensors correct for this using a cosine correction filter which you won’t get with the phone apps or perhaps a ‘guestimation’ version on some of the lower end sensor (e.g. a diffuser).
But, again, hand-grenades.
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This is very obvious with the Pulse. I agree that it is the difference between a nice Bluelab pH pen and a cheap Hanna pH pen. If you are doing DWC you probably want the nicer pen, if you are doing organic the Hanna is probably good enough.
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I don’t disagree. I just feel the 40 ppfd difference that was noted when the Photobio was within acceptable levels for my purpose. Same with the Pulse Pro that showed a difference of 30 ppfd. These are plenty accurate for my purposes.
I certainly would not want to try to use my meter to do a scientific paper for publication, I would want the most accurate data I can get. I can’t argue that the top of the line models are better. I just feel ones like the Pulse Pro and Photobio are suitable for a grower.
Hey Loki, what is et al? I have heard of Apogee and Li-cor, who was the last one you quoted?
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et al = and others.
I wouldn’t go overboard with that claim. There’s more underlying detail. Cosine angle, spectral response, linearity, etc. The check does tend to say that it’s more than good enough for general purpose use. The apogees themselves have a +/- 5% calibration tolerance and a 1% repeatability specification. At 1K that’s a 100 PPF calibration uncertainty along with up to a 20 PPF band of measurement uncertainty.
Reality says such errors, if they occur, will not matter under most use situations. It mostly becomes important under certain circumstances which broadens the range of use-ability … which usually means more expense. It is also why it’s good to have such discussions such that folk understand that there may be circumstances a sensor may or may not be appropriate for the task at hand. A variation of ‘best for the money’ vs ‘the best’ for any specific task.
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Just my two cents… I’m a scientist by training (organic chemist, radiochemistry and pharmacology) — Rating a tool that measures something requires a standard that everyone has access to.
I’ve got the new apogee meter, and I’d be interested in collaborating with you all to see if we can get to the bottom of this since we have the meters…
I’d suggest we get a few LEDs off Amazon that we can confirm are mostly identical and take measurements with the different meters. If they show unity in terms of the ppfd I think the easy answer here is that they are all just as good as one another.
If they do not… then we will have to determine what the issues are. That’s pretty typical science, though. If it were easy, someone would have already done it.
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Got it, thanks
Enjoy your meter. I like my Apogee. I know it’s a proven and documented product. If you have faith in what you use that’s what counts for you.
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I just need something that wont break the bank and give me some round about numbers. My caveman PAR meter (hand) only works so well.
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I do enjoy it thanks, it’s a good tool. I do have faith in a product that works and was tested against top meters by someone I know. It’s not that it works for me but rather that it just works. While I wont argue that the Apogee is better mine is more than accurate enough for testing lights to grow weed. Spending 3 times the money to get something slightly more accurate is not worth it to me. For those who want to spend the extra for better accuracy I say good on them. You wont find me talking down folks who spend the cash to get top tier products. There is no debate about the MQ500 being a top tier unit and I would hope you like it, I would if I had one. It’s really just that something that’s 1/3 the cost with reasonable accuracy is more than good enough for my purposes and I would guess would be for most. Happy growing 
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Nice bud, hope it serves you well.
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Yes indeed and I appreciate you expounding on these things. I am surely no expert nor does one test from one grower tell a full story. The wealth of knowledge you bring to such discussions is always welcome and appreciated.
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I used to recommend the Photone app all the time. I got an sq-500, and used it’s readings to calibrate the Photone app. I updated the app quite at some point (probably multiple times) though, and I tended to use the app (android, by the way, which makes a big difference compared to the iPhone version) more because it was more convenient (my sq-500 needs a usb connection to some screen device).
This last run, I was using Photone, and after a few checks over the weeks, I started to really doubt the readings I was getting. I hooked up the sq-500 and I was pretty shocked. The readings were something like 50% higher than what the Photone app was telling me. That could mess things up. Photone read this one particular area/bud site at around 800ppfd, Apogee read 1200+ppfd. As I read the numbers out, moving the sq-500 around I was seriously surprised.
I just thought of this because my veg is looking a little weird. They’re under qb132’s, I think, not particularly powerful boards. Well, with the plants now nearly touching the boards (I always say it’ll be the last time I do this) the ppfd was something like 850-1000+. The intensity seems to increase at a more rapid rate with these boards than with their qb288 or qb648 boards (though I duno if that’s actually the case, with the inverse square law and all that - @Northern_Loki might know off hand).
I have to keep the veg boards on max because they’re at a fixed height (the ceiling, basically), but then they grow up into much higher ppfd, and I should be either changing stuff (fertilizer strength, for eg.) or not doing this - and keeping distance the same-ish, instead.
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@DougDawson
Your take on ph meters is backwards
Blue Lab is hobbyist level toys r us meter’s (vs dollar tree Amazon meters)
Hanna is real deal scientific quality.
But you have to maintain them properly like a jigh precision lab measurement device should be
I think you tagged the wrong person. You responded to a post by @ReikoX , not me?