Lux Meters

To minimize calculations and guessing and to maximize reflected light to our plants, we will need a light intensity (Lux or foot-candle) meter of one type or another. We will ultimately need a table of minimum to optimum Lux for a given hours per day for each class of plants we intend to grow. To balance the red and blue intensity, some of us will need to measure to an extent color, chromaticity, or Kelvin temperature. Where to buy a Lux Meter? The following are some of the alternatives.

LX-101 $65.95
LX-02 $39.00
Extech Model 401025 $119

I know that a light intensity or Lux meter can be built out of a simple solar cell and a digital current meter for less than $20. The question is if one did this without a reference meter as a standard, how does one calibrate it? All I can think of right now is a candle one foot away for the low end and the sun for the high end. Aside from there being no sun after the pole shift, neither is a good stable, non-variable source. Building a color or Kelvin meter is another story. Possibly using the same Lux meter with some color filters would serve our purpose.

Offered by Mike.