crumbletop
New member
Anyone in the club have a PAR meter that I could borrow?
PAR meter
- Thread starter crumbletop
- Start date
crumbletop
New member
If the club had one, would others be interested in using it? You can get one for around $200 - $250 that appears to have a waterproof sensor. I'm curious about the PAR levels at different parts of my tank. If enough other people are interested as well, maybe the club would consider purchasing one.
There is a thread here, where the Chatt reef club is looking to get one:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=946756
There is a thread here, where the Chatt reef club is looking to get one:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=946756
crumbletop
New member
Well, I know c_stowers would be interested in using one. He and I were talking about one the other day. He's out of town right now.
For those who don't know what a PAR meter is, it basically measures the intensity of <b>P</b>hotosynthetically <b>A</b>ctive <b>R</b>adiation (PAR) which is basically the intensity of light in a spectrum range that corals like. You can use it to measure the output of your light setup at different depths.
Anyone else interested?
For those who don't know what a PAR meter is, it basically measures the intensity of <b>P</b>hotosynthetically <b>A</b>ctive <b>R</b>adiation (PAR) which is basically the intensity of light in a spectrum range that corals like. You can use it to measure the output of your light setup at different depths.
Anyone else interested?
Pickupman66
New member
it might be a cool tool to use. my only hangup is how much repeat use it might get. I would use it once for sure, just to see what I have. maybe use it if I upgrade lights.
crumbletop
New member
Well, you can use it also to see what the output is doing over time with your lights. I know c_stowers just had some issues with a halide (hamilton?) when it neared the year mark. He just switched to an Ushio 14K. My guess is each of us individually wouldn't use it that often, but as a club resource it might be nice to have.
bkv1997
New member
We just ordered one for the chattanooga club. Like you said not something an individual would use often, but would be great to have as a club.
http://www.apogee-inst.com/bqm_spec.htm 3rd one down on the list.
It should be here pretty soon, so if anyone is interested I can let you know how it turns out.
http://www.apogee-inst.com/bqm_spec.htm 3rd one down on the list.
It should be here pretty soon, so if anyone is interested I can let you know how it turns out.
crumbletop
New member
Cool. Yeah, that's one that says the probe is water proof, and I like that there is 6' of cable between the probe and the display. Yeah, I'd love to hear how it works -- and then I can bug Gary to get one for us
Brian: yeah, that's a good idea too. I think something like that would be helpful to know.
bkv1997
New member
No problem, I'll let you guys know. Infact our Nov. Meeting is at my house on 11-11 if anyone wants a in person look at it.
Keeping the data for comparison is a great idea if done right...., but a strict set of guidlines would need to be set up front.
Example:
1) Clean Bulbs/UV Shield no salt creep.
2) Make a device so that the Sensor is always exactly horizontal
3) All pumps turned off. Water surface movement can skew results.
4) Distance from lights to water and then from water to sensor would have to be defined up front.
5) Bulbs should always be tested new after about 60 hours use.
6) You only compare same spectrum bulbs. PAR sensors don't pick up blue light perfectly and over compensates for yellow light.
etc... you get the idea and probably already knew that, but just thought I would mention it just incase.
Keeping the data for comparison is a great idea if done right...., but a strict set of guidlines would need to be set up front.
Example:
1) Clean Bulbs/UV Shield no salt creep.
2) Make a device so that the Sensor is always exactly horizontal
3) All pumps turned off. Water surface movement can skew results.
4) Distance from lights to water and then from water to sensor would have to be defined up front.
5) Bulbs should always be tested new after about 60 hours use.
6) You only compare same spectrum bulbs. PAR sensors don't pick up blue light perfectly and over compensates for yellow light.
etc... you get the idea and probably already knew that, but just thought I would mention it just incase.
cee
New member
Nail on the head...
The cheaper units are for industrial lighting, and therefore optimized for yellow/green spectrum. For 20k bulbs, they do not give an accurate representation, and without spectral data and response curves, absolute PAR cannot be measured. For a given color temp bulb, they can be useful for bulb comparison, however. They are also useful to measure lighting uniformity, bulb aging, and attenuation with water depth, bulb height above surface, etc.
Dave
The cheaper units are for industrial lighting, and therefore optimized for yellow/green spectrum. For 20k bulbs, they do not give an accurate representation, and without spectral data and response curves, absolute PAR cannot be measured. For a given color temp bulb, they can be useful for bulb comparison, however. They are also useful to measure lighting uniformity, bulb aging, and attenuation with water depth, bulb height above surface, etc.
Dave
Pickupman66
New member
Hey, you guys may want to check out this months reefkeeping magazine. GREAT article in regards to Par.
crumbletop
New member
Thanks!
That gives me more ideas about measuring PAR in my own tank. In particular, I am experimenting with smaller reflectors on my T5's so as not to blanket the whole tank with tons of light. I cut up some of my long reflectors into 7" pieces that I am using on each side of my 90. So instead of the entire tank being covered by reflectors, only a 7" strip in the middle of each side is. It would be nice to see the intensity spread that they provide, and then compare that to some point light sources. Not compare absolute values, but relative % decrease as the distance from the center of the point source increases. I'm also curious about the change in intensity at different points under the reflectors if I angle some of them rather than have them all pointing straight down -- allowing for a blending of bulb spectrums rather than focusing each bulb narrowly along the bottom of the tank.
Boy -- now even more questions are coming to mind
That gives me more ideas about measuring PAR in my own tank. In particular, I am experimenting with smaller reflectors on my T5's so as not to blanket the whole tank with tons of light. I cut up some of my long reflectors into 7" pieces that I am using on each side of my 90. So instead of the entire tank being covered by reflectors, only a 7" strip in the middle of each side is. It would be nice to see the intensity spread that they provide, and then compare that to some point light sources. Not compare absolute values, but relative % decrease as the distance from the center of the point source increases. I'm also curious about the change in intensity at different points under the reflectors if I angle some of them rather than have them all pointing straight down -- allowing for a blending of bulb spectrums rather than focusing each bulb narrowly along the bottom of the tank.
Boy -- now even more questions are coming to mind
