Light meter recommendations

[derv88]

Does anyone have recommendations for a solid and accurate light meter for indoor growing under lights?

I've screwed around with iPhone apps and I am just not trusting the readings I get. For example, I thought I had finally found a decent app that is made for this purpose called "Green Thumb(s)" or similar, I was excited when I first took measurements sometime in August that my Catt shelf lighting was putting out around 2500 fcs - right where it should be - and my Phal/Paph shelf was around 1500 fcs also within the target range.

Figuring the bulbs may be aging, and to get a more recent reading - I remeasured today and the readings were dramatically different - around 1500 fcs for the Catt shelf and less than 1000 fcs for the Phal shelf.

If these new readings are right, my 4" T5HOs are wearing out quickly...I just don't trust these readings and need accurate measurements to ensure that my light output is within range.

Does anybody have any suggestions for an accurate light meter that measures in fc's and won't break the bank?

Thank you in advance!

[RNCollins]

[naoki]

Well, I'm not sure if you need an accurate lux meter, but this one seems to be ok.

http://www.amazon.com/Dr-Meter-Digit...ds=light+meter

The spectral response could be quite different from one model to another (for consumer-level product). These lux meters are sensitive to green light, but less sensitive to red and blue light. This sensitivity for different kinds of light can be described by "spectral response" curve. There is a standard response (CIE curve), but many consumer meters deviate from it. This means that you might not be able to compare the reading of one meter with another person's reading especially if you are using it for artificial lighting.

With this meter, the user manual has a spectral response curve which is very close to CIE standard (a good thing). However, we don't know if the data is real or not.

PAR meters are better, but unfortunately, they are not cheap.

[katrina]

I have the model Naoki recommended. I got it on eBay several years ago and it works great.

BTW - it measures footcandles as well as lux.

[derv88]

Thank you! Purchased. Will report back on UE.