Light Meter
 

I recently bought a light meter to make sure my orchids get the proper light. I must confess I am having a bit of a time understanding it. :blushing:
If I have the setting on X1 the instructions say that is an Over-Input with a display reading of '1'.
When I move the switch to X10 and move the sensor about 6" from the fluorescent lamp it reads 43.3
At X100 it's 04.3 Am I supposed to put zeros on the end? At 4300 footcandles it seems too much and at 430 fc not enough. It is an agricultural light meter, not for photography.

I would need to read the directions. Are they available online (probably?)

43.3 x 10 = 433 (maybe fc not lux, right?). Is it 1 or 2 bulb T8? Then it's probably not far off. I get about 288fc at 12" from 2x old 32W T8 (Philips F32T8/TL850). Some Phals would be ok with 500fc. You can get constant amount of light (unlike natural light where you get the peak intensity around noon), so the cumulative amount of light (called Daily Light Integrals) could be enough.

Over input means that the numbers are overloaded, a bit when you multiply two big numbers together on a calculator, and the sum is too big for the display, so it reads 'E'.

if the reading is 43.3 at the x10 position, the actual reading is 433.

The directions are very scimpy. The manufacturer is 'Sunleaves' sungauge. At: sunleaves.com There was not much there. I suppose they figure that one knows what one is supposed to do. (not)

---------- Post added at 11:33 AM ---------- Previous post was at 10:56 AM ----------

It's a 2 light, 48" cool white T12/DX 40 Watt Philips
If Phals are OK with that, what about Catts and others?

T12 40W has similar total output as T8 32W (so T12 is much less efficient). So 433fc is in the correct range.

I could flower a hybrid Catt under 2x T12 30 years ago, but it is a bit low for Catt. You could try to put the leaves as close as possible without burning them. If the distance becomes half, you are getting 4 times more light.

Your catt will need a lot more than your phals. I got one of those light meters too and I find them confusing. I go by how your plant does. If your catt leaves are too dark green then up the light. I have my plants on a North window. The lights I add are (3) T8 per shelf, or a combo of (1) T8 & a T12. I have a nice color and have rebloomed with those lights. The phals actually get a shear curtain.