What's new
  • ICMag with help from Landrace Warden and The Vault is running a NEW contest in November! You can check it here. Prizes are seeds & forum premium access. Come join in!

ppfd v lux readings. Help Me..

f-e

f-e

Well-known member
Mentor
Veteran
10k.. Standard daylight. I bring things on at that. Perhaps 150-200umol/s. I think the phone sensor isn't concerned with much other than screen dimming, and if it's in your pocket or by your head. A basic LightDependentResistor perhaps. The App is taking information from the operating system, that in turn has no interest in recording levels above daylight.

So I aimed for 700umol, I shot, I failed. The hid plants were fine, but the led one's showed every problem known to man. ec1.7 wasn't enough, but my vpd was also boarderline while it filled up. 550umol now, and a nice vpd. They did grow like fuck though. First K issue's in ages, mostly seen on an isolated control. So vpd seems the real problem. So glad I didn't do a diary lol

Nice looking meter SBG. I'm starting to think one with built in sensor is best for tweeking controls while taking a reading.
Mine
https://www.icmag.com/ic/showthread.php?t=314806

Something on the underground, but I'm not sure it's the full article. I read so much. https://www.ee.co.za/article/extraordinary-measures-role-lux-meter.html
 
I'mback

I'mback

Comfortably numb!
f-e said:
10k.. Standard daylight. I bring things on at that. Perhaps 150-200umol/s. I think the phone sensor isn't concerned with much other than screen dimming, and if it's in your pocket or by your head. A basic LightDependentResistor perhaps. The App is taking information from the operating system, that in turn has no interest in recording levels above daylight.

So I aimed for 700umol, I shot, I failed. The hid plants were fine, but the led one's showed every problem known to man. ec1.7 wasn't enough, but my vpd was also boarderline while it filled up. 550umol now, and a nice vpd. They did grow like fuck though. First K issue's in ages, mostly seen on an isolated control. So vpd seems the real problem. So glad I didn't do a diary lol

Nice looking meter SBG. I'm starting to think one with built in sensor is best for tweeking controls while taking a reading.
Mine
https://www.icmag.com/ic/showthread.php?t=314806

Something on the underground, but I'm not sure it's the full article. I read so much. https://www.ee.co.za/article/extraordinary-measures-role-lux-meter.html
Click to expand...
We often spend more time worrying more about PH and nute defs vice VPD, that can play havoc on our grows. but when you dial both in, :biggrin: :tiphat:
 
SuperBadGrower

SuperBadGrower

Active member
f-e

f-e

Well-known member
Mentor
Veteran
Looking aimlessly at my screen, I focused on the apogee small print. They have an app online. You can upload your own leds to see how they work with their meters. The app already has a few more light sources, such as a couple of fluence lights.

The file type is awkward. It's a simple text file. While samsung offer at least half a dozen 3dcad type files. Perhaps a conversion is not so hard, but I'm pushed to say the least. I have never looked at either.
 
f-e

f-e

Well-known member
Mentor
Veteran
Some timer ago I collected a lot of info together, with the lux/ppfd conversion figures for the R-spec from HLG themselves. Since this time I have struggled with why I'm burning twice the power I should be to get the ppdf on the box. Finally coming back to the fact HLG must of got it wrong.
This is that image that I feel should be discarded

Damn broken album again, not an image in sight...

Fresh upload...
umol-lux.jpg


There we see 39,000lux is 600ppfd.
Here is MIGRO from a video showing the actual meter being used, and the result is 25,000lux for 600ppfd.

Oh this is impossible, I will post again, please don't interupt my flow..
 

Attachments

  • photo2032725.jpg
    photo2032725.jpg
    104.7 KB · Views: 98
f-e

f-e

Well-known member
Mentor
Veteran
To get a third opinion, We see another meter being used with a light commonly seen here from Mars.
MARSppfdmeter.jpg


Here we have 31,000lux to achieve 500ppfd which is actually the other side of the HLG figures, I was so quick to discard.


If nothing else, this may guide you to buy a known meter and have an idea what it should say.

I actually hoped to find the cheapest of cheap meters, the $10 one beside a PAR meter. If anyone has a par meter and something like lm301s+660s and half an hour, I would happily post you the cash to buy a tacky meter and do something like the tests above.
 
ledtime

ledtime

Member
f-e said:
To get a third opinion, We see another meter being used with a light commonly seen here from Mars.


Here we have 31,000lux to achieve 500ppfd which is actually the other side of the HLG figures, I was so quick to discard.


If nothing else, this may guide you to buy a known meter and have an idea what it should say.

I actually hoped to find the cheapest of cheap meters, the $10 one beside a PAR meter. If anyone has a par meter and something like lm301s+660s and half an hour, I would happily post you the cash to buy a tacky meter and do something like the tests above.
Click to expand...

I have a lux meter somewhere. I'll see if I can find it and see how it translates to my apogee sq520.
 
ledtime

ledtime

Member
f-e said:
To get a third opinion, We see another meter being used with a light commonly seen here from Mars.


Here we have 31,000lux to achieve 500ppfd which is actually the other side of the HLG figures, I was so quick to discard.


If nothing else, this may guide you to buy a known meter and have an idea what it should say.

I actually hoped to find the cheapest of cheap meters, the $10 one beside a PAR meter. If anyone has a par meter and something like lm301s+660s and half an hour, I would happily post you the cash to buy a tacky meter and do something like the tests above.
Click to expand...

You could also use the lux app on your phone too?

Migro has a video on their YouTube that helps with using the phone lux meter and converting
 
chilliwilli

chilliwilli

Waterboy
Veteran
Hi folks please look at riu thread math behind from the user alesh.

i found the ler/qer calculator(.ods) on grower.ch and downloaded from there. Big thx to user tomate.
 

Attachments

  • math_2.0.1.ods.zip
    81 KB · Views: 122
f-e

f-e

Well-known member
Mentor
Veteran
Click image for larger version Name: meter.jpg Views: 0 Size: 184.9 KB ID: 17834397

Finally, the cheapest meter on the market, beside a meter that's been beside a PAR in capable hands(that can correct for the fact it's LEDs)

When cheap meter says 20,000 we should have 600ppfd



I like the 3:1 ratio, that says my grey meter at 25 will be 75 (or 25,000 = 750)

In the pic, the grey one shows 404 (x10) so 4040 actually. Times our 3, that's 4x3=12 so realistically 120ppfd as it can't be 12 or 1200 (we would see it)


If I'm jumping around to much there, the actual math for the grey meter is Reading in lux, Times by 3, then divide by 100. So 4000 x 3 = 12000 and 12000/100 = 120ppfd (or as I did, 4x3=12 so 120ppfd... surely)
 
You must log in or register to reply here.

Latest posts

Latest posts

Top