Looking for a used par meter

[mcarroll]

If you look around the plant forums a bit, people have converted our trusty LX-1010B to be a PAR meter with some simple mods to the sensor.

Yes, for curiosity, I'd like one too - but I still can't get around the fact that I'm getting the job done with a $15 LX-1010B and just measuring at the water surface.

Here's a DIY PAR meter design that's been around quite a while:
http://www.plantedtank.net/forums/20-diy/120109-diy-par-meter-yeah-you-heard-me.html#post1197502

It's been quite a while since I read any of this, but I don't think that's the same as the conversion thread I mentioned above (no mention of the LX-1010B, in other words)....but it is the thread I was wanting to share. Getting old...sources sometimes blend a little on the periphery.

 

[mcarroll]

@jjbunn that last post was for you.

 

[jjbunn]

@jjbunn that last post was for you.

Thanks - good stuff!

I made a set of RGBW measurements 3" under the Mars Aqua unit, and tabulated them alongside the ones in the table I linked. Then I ran a fit to a linear function, that gives me PAR given a set of RGBW values. Now I've implemented those in my app, and am doing some tests. The upshot is that if I position the phone 3" under the light, then I get PAR readings that quite closely match the table.

 

[jjbunn]

Anybody with a Samsung S4 and a PAR meter want to try the app? It would be useful to get more calibration data, to improve the PAR estimation. Here's a screenshot of what it looks like. The R, G, B and W sensor values (in Lux) are shown, together with the estimated PAR value. (The screenshot was taken with the sensor very close to the Mars Aqua array.)

I'm not sure if any other phones use the CM3323 sensor, so right now the app is only known to work on the Samsung S4.

 

[saltyfilmfolks]

Anybody with a Samsung S4 and a PAR meter want to try the app? It would be useful to get more calibration data, to improve the PAR estimation. Here's a screenshot of what it looks like. The R, G, B and W sensor values (in Lux) are shown, together with the estimated PAR value. (The screenshot was taken with the sensor very close to the Mars Aqua array.)

I'm not sure if any other phones use the CM3323 sensor, so right now the app is only known to work on the Samsung S4.

pm coming.

 

[Scott.h]

I don't understand this. I'm in the middle of setting up a frag tank. I have a four ballast T5 HO With brand-new bulbs. You can't fit more bulbs on top of this Tank. These are the readings that I'm getting. So in order to do SPS I would have to cram everything just under the water surface?? Look at these numbers

 

[saltyfilmfolks]

Umm it goes from 10o,000 lux to 4600 in four inches. Are you using a meter or phone. For that stuff you need a meter. The phone is neat. It'll get you an idea but it's a phone.

And not all SPS need high light btw.

 

[Scott.h]

It's two days old. I moved it around and checked it twice..

It dropped like that because it went under the surface of the water

 

[saltyfilmfolks]

Uhh really weird. From 1000000 to 4600 Are you sure it's not 46000

 

[saltyfilmfolks]

Just one t5 at 4 or five inches is about 23000
With good reflectors and depending on the tubes I would have guessed 35000 maybe maybe at the top of that tank.

 

[Scott.h]

Yeah it's 4 24" tubes with reflective hood. 2 blues, two whites. New. The meter read 460 on the top setting, which is times 100. I also took the meter to the LFS and checked 3 different coral tanks of theirs. All of theirs are LEDs but I got drop off readings similar to my display LEDs. Par reading around 260 at the top and under 50 at the bottom. So either the math is off or the meter isn't correct. I'm not sure. I'd really like to see an apogee to compare this. I think I may and make a holder to check both meters side by side and see.

 

[Lenny_S]

FWIW I found a Seneye Reef package on Bonanza for $159. It's about the least expensive PAR & Spectrum meter I've seen. I think if you really want to know, that would be the way to go.

 

[saltyfilmfolks]

Yea 46k sounds better. The constant to devide by it tricky to research. But if you go at 60. Or 67 for a really nice fixture you get close.
A funny thing to is the side by side comparison of par meters accuracy will still leave questions. They are not all going to give the same reading.
So fifty par at the bottom of the tank is not so bad

 

[Scott.h]

True which is why I took the meter to the fish store. Really the numbers doesn't matter as long as they are measured to compare with something reputable. And to know bulb quality drop over time.

What do you mean when you say "go at 60 or 67" though?

 

[Scott.h]

FWIW I found a Seneye Reef package on Bonanza for $159. It's about the least expensive PAR & Spectrum meter I've seen. I think if you really want to know, that would be the way to go.

I was debating on that one earlier but didn't see much info on it. I am curious as to know how it works as it is considerably cheaper then the apogee

 

[Lenny_S]

I was debating on that one earlier but didn't see much info on it. I am curious as to know how it works as it is considerably cheaper then the apogee

From what I can tell you get some software with it and need to connect it to a computer to use it. But the PAR meter does PAR and color temp... For spot measurements it seems fine, not sure how well the basic kit would work for continuous monitoring or how convenient it would be.

 

[jjbunn]

Anybody with a Samsung S4 and a PAR meter want to try the app? It would be useful to get more calibration data, to improve the PAR estimation. Here's a screenshot of what it looks like. The R, G, B and W sensor values (in Lux) are shown, together with the estimated PAR value. (The screenshot was taken with the sensor very close to the Mars Aqua array.)

I'm not sure if any other phones use the CM3323 sensor, so right now the app is only known to work on the Samsung S4.

Still working on this. I took the phone out in bright sunlight, which maxed out the RGBW values to 65536 (evidently a 16 bit readout from each sensor channel), which resulted in a PAR reading of 2400 using the calibration fit from the Mars Aqua. This sounds about right as according to Dana Riddle http://www.advancedaquarist.com/2005/7/review sunlight is approximately 2000 PAR.

Also I used the Amazon AWS device pool to test which Android phones will work with the app (it depends on them using a particular type of light sensor, that writes data in a specific location in the fs - just using the SDK's built in lux value is insufficient, I believe). This turned up the following two phones that use the CM3323 sensor:

Galaxy S4
Galaxy Tab S2

and the following phones that use a different sensor which is compatible:

Motorola Nexus 6
Motorola Moto G
Motorola DROID Ultra
LG NEXUS 5
LG G3
HTC One M8
Galaxy Tab S2 9.7
Galaxy S6 Edge
Galaxy S6
Galaxy S5
Galaxy S4
Galaxy S3
Galaxy Note II
Galaxy Note 5
Galaxy Note 4
Galaxy Note 3
Galaxy A5

Anyway, I'm not sure this thread is the right place for all this info, which is perhaps of very marginal interest I'll put the app on the Play Store, as I'd love more people to try it out and send me some feedback - especially if they can directly compare measurements with a PAR meter

 

[Scott.h]

There isn't one available for Apple?