Lets Talk Inexpensive PAR Meters....

[HydroRed]

As the title suggests, I'm looking to buy an inexpensive PAR meter and was looking for opinions from people who actually own one, and use it. I'm new to this realm of equipment & I dont really know where I should begin? What makes one better than the other? Why such drastic price swings between manufacturers and models?
Factual experiences and links to equipment are more than welcome. -Thanks in advance

 

[BOBBY_G]

What makes one better than the other?

accuracy in response in the par range.

http://www.advancedaquarist.com/2013/2/equipment


as far as affordable (<$500) accurate sensors you have few options
licor li 190 is the standard for decades but is not really 'affordable' new

and the new 'full spectrum' apogee MQ/SQ500 does a lot better than the MQ/SQ 200 thats been around and sold as apogee and sun systems

Why such drastic price swings between manufacturers and models?

because scientists who need accuracy will pay $2000 for a li-cor setup

used li-cors show up on ebay from time to time, i grab them and have 3 right now (gearslut). i have 2 of the analog li-185 meters like this:

http://www.ebay.com/itm/LI-COR-QUANTUM-RADIOMETER-PHOTOMETER-LI-185-/361460502244?hash=item5428b98ee4:g:COEAAOxyrxZRyY3T

they were a little over $200 with sensor

then i came across a digi li-250 w/sensor for $400 and snagged it

the new licor sensors alone are like $450 and then you need a meter like that $100 analog one on ebay or you might catch an LI-250 under $500

http://www.fondriest.com/li-cor-li-190r-par-sensors.htm

the apogee sensors alone are $295 and can be read and converted with a multimeter

http://www.apogeeinstruments.com/sq-500-full-spectrum-quantum-sensor/

the apogee MQ500 with meter and sensor are $500

http://www.fondriest.com/li-cor-li-190r-par-sensors.htm

a better deal is prob the apogee SQ500 USB it can do it all and is $345 BUT needs a computer so not so easy to use in our applications. it can log at intervals which is cool

http://www.apogeeinstruments.com/sq-520-smart-quantum-sensor-usb-output/

as far as an affordable out-of-the-box somewhat accurate par sensor the new apogee is decent, remember it weights blue by about 10% you may be able to account for LER and correct

 

[sixstring2112]

so is this a decent deal ? https://premiumaquatics.com/products/apogee-mq500-full-spectrum-quantum-meter.html
i been wanting one that is on the user friendy side for a while now.i dont mind paying more for something better but i doubt i would drop 2 grand on a meter.

 

[HydroRed]

Thanks for taking the time to help me understand more about these meters @BOBBY_G . This is a new hobby and seemingly expensive in all aspects as well. I could spend a little for a meter but Im not that serious about it to need that expensive of equipment to "play".
Would this be an ok buy for someone who doesnt need exacting scientific numbers/data logging? This is more my price range to "play".
http://www.neobits.com/hydrofarm_lgbqm_quantum_par_meter_p7363839.html?atc=gbp&gclid=CKqtuamZlc0CFQEdaQod-VAOKQ


I'm looking to just check my diy 400W led light and see what its putting out next to my 1k hps in the same foot print. Plus it wouldnt hurt to have one around to use for future builds or add ons to current builds etc.

 

[BOBBY_G]

so is this a decent deal ? https://premiumaquatics.com/products/apogee-mq500-full-spectrum-quantum-meter.html
i been wanting one that is on the user friendy side for a while now.i dont mind paying more for something better but i doubt i would drop 2 grand on a meter.

If they have stock... apogee site has 6 week back order

http://www.apogeeinstruments.com/mq-500-full-spectrum-quantum-meter/

 

[BOBBY_G]

Thanks for taking the time to help me understand more about these meters @BOBBY_G . This is a new hobby and seemingly expensive in all aspects as well. I could spend a little for a meter but Im not that serious about it to need that expensive of equipment to "play".
Would this be an ok buy for someone who doesnt need exacting scientific numbers/data logging? This is more my price range to "play".
http://www.neobits.com/hydrofarm_lgbqm_quantum_par_meter_p7363839.html?atc=gbp&gclid=CKqtuamZlc0CFQEdaQod-VAOKQ

I'm looking to just check my diy 400W led light and see what its putting out next to my 1k hps in the same foot print. Plus it wouldnt hurt to have one around to use for future builds or add ons to current builds etc.

if you need to compare different spectrums/techs you need an accurate meter

if you just need to check for light intensity of a given setup - which is far more important imo - finding the hotspots and darkspots in your grow - any cheap ass lux meter will do (thats all that hydrofarm is - an overpriced cheap lux meter). just take the results relatively for what they are worth and dont get hung up on the units

http://www.ebay.com/bhp/lux-meter?rmvSB=true

 

[HydroRed]

if you need to compare different spectrums/techs you need an accurate meter

if you just need to check for light intensity of a given setup - which is far more important imo - finding the hotspots and darkspots in your grow - any cheap ass lux meter will do (thats all that hydrofarm is - an overpriced cheap lux meter). just take the results relatively for what they are worth and dont get hung up on the units

http://www.ebay.com/bhp/lux-meter?rmvSB=true

I was under the impression lux meters dont work very good with led?

 

[BOBBY_G]

they are not absolutely accurate - but as i stated above EVEN coverage of any given light is far more important than if you have 800 umol and your bro across the street has 820. because at that point, water, nutes, training, temp, humidity, etc etc. all impact A vs B results

 

[dionysus4]

i agree with bobby, if its for your garden you dont need accurate data just relative

geta cheap lux

 

[Stephenj37826]

Cheap lux is fine especially since you can get a rough estimate of par if you know QER/LER

 

[alesh]

Cheap lux is fine especially since you can get a rough estimate of par if you know QER/LER

...and the meter's response...

 

[Atulip]

I'm a big fan of a cheap lux meter. Definitely useful for getting even coverage.

You can also work the math backwards with a lux meter. I like to keep the conversion number handy for quick calculations from Cree PCT. Qer 4.6 / ler 324 = .0142

40,000 lumens * .0142 = ppf of 567

 

[Bill Lidgate]

if you know the spectral distribution of your lights (easily gotten with a $10 spectrometer*) you can generalize the response of a cheap LUX meter (usually centered at 550nm) to be equivalent to a true quantum meter for simple analyses like light distribution. I'd only think of a quantum meter if I had next to no light at 550nm (or had too much $).

*https://publiclab.org/wiki/spectrometer

 

[alesh]

if you know the spectral distribution of your lights (easily gotten with a $10 spectrometer*) you can generalize the response of a cheap LUX meter (usually centered at 550nm) to be equivalent to a true quantum meter for simple analyses like light distribution. I'd only think of a quantum meter if I had next to no light at 550nm (or had too much $).

*https://publiclab.org/wiki/spectrometer

To do so, you also need to know the spectral response of that cheap lux meter.

 

[JorgeGonzales]

I was under the impression lux meters dont work very good with led?

It depends on what you are trying to achieve. If it's calculating PPFD, that's hard with a lux meter. If it's spacing DIY lights, testing reflectors, anything where you are comparing relative amounts of light from the same CCT leds, that's easy.

Comparing to HPS falls under the hard category.

 

[HydroRed]

It depends on what you are trying to achieve. If it's calculating PPFD, that's hard with a lux meter. If it's spacing DIY lights, testing reflectors, anything where you are comparing relative amounts of light from the same CCT leds, that's easy.

No ppfd calculations, just simple comparisons on light saturation between the 1k HPS and 400W led over the same footprint along with spacing etc as you mentioned. Nothing exacting, but give a general idea of where Im at in my grow rooms. Its looking like a lux meter is what I'll need....which after seeing prices on par meters -I'm cool with that. Im realizing quickly that the title of this thread is an oxymoron. haha

 

[HydroRed]

Damn, I just caught this part of your comment:

Comparing to HPS falls under the hard category.

Im looking to compare the two in the same footprint. I cant use lux to compare between the two?

 

[Atulip]

Spread is fine, and even a generalization of light levels, .0122 conversion for hps.

 

[PurpleBuz]

Im looking to compare the two in the same footprint. I cant use lux to compare between the two?

if you can afford a wee bit more, I suggest using the apogee sq-100, sq-200. Will do better than a lux meter, While the apogee is weak in the deep red region, it at least doesn't bias it into the narrow human lumens bandwidth. With the wide variety of spectrums that different grow lights are producing nowadays seems prudent to not use a lux meter, unless all of your lights have a very similar spectrum.

 

[JorgeGonzales]

Damn, I just caught this part of your comment:

Im looking to compare the two in the same footprint. I cant use lux to compare between the two?

Picture it like this. A lux meter weighs every photon arriving at it's sensor, and gives the most weight to green with a peak at about 550nm, right? Because that's how our eyes work.

So pretend you have a meter that only reads green light. You have two lights, Light A is 50/50 green and blue, Light B is 100% green light. They are making the same amount of light but your meter says Light A is half as powerful. This is the problem using lux meters to compare two lights, in a worst case scenario.