What are the units for the light meter? lumens, lux, footcandles, PPFD?
1750948
based on weather reporting of solar energy and the scale 0 to 2000, it is watts per meter squared (w/m2)
1750949
The meter only has a guage that reads, 0 to 2000 on top and 1 to 10 on the bottom of the line...I only paid less than $4.00 for the meter including shipping from China... It has saved me from over watering. The meter seems to be working ok but I don't know how accurate it is... For a cost of less than $5.00 it can't be too percise...
1750950
I checked the unit and it really doesn't say. The light scale runs from 0 to 20,000. The only directions that came with it were on the back of the package, and there wasn't a lot more than general directions. Sorry.
1547942
I buy a luxmeter of this brand and capacity, and has the ability to measure light from 0.1 lux to 200,000 lux, divided into 4 types of measurement ranges.
802250
It should be noted that "lumen" can mean many things depending on how you obtain a lumen measurement. At one foot away with the "zoom" at max spread the light produced 4800~4900 lux which is about 450 lumens/sq ft. Though when focus to a point the light produced over 90,000 lux which is about 8,300 lumens/sq ft. Unless you can find definitive data that explains the lumen of this light (or any other light in existence) the advertised brightness of a flashlight is meaningless. It's would be better to look up the datasheet for the Cree XML emitter and search for visual examples of the light (using quality 3.7V 18650 Li-Ion bats of course). It should be noted that "lumen" can mean many things depending on how you obtain a lumen measurement. At one foot away with the "zoom" at max spread the light produced 4800~4900 lux which is about 450 lumens/sq ft. Though when focus to a point the light produced over 90,000 lux which is about 8,300 lumens/sq ft. Unless you can find definitive data that explains the lumen of this light (or any other light in existence) the advertised brightness of a flashlight is meaningless. It's would be better to look up the datasheet for the Cree XML emitter and search for... » Read More It should be noted that "lumen" can mean many things depending on how you obtain a lumen measurement. At one foot away with the "zoom" at max spread the light produced 4800~4900 lux which is about 450 lumens/sq ft. Though when focus to a point the light produced over 90,000 lux which is about 8,300 lumens/sq ft. Unless you can find definitive data that explains the lumen of this light (or any other light in existence) the advertised brightness of a flashlight is meaningless. It's would be better to look up the datasheet for the Cree XML emitter and search for visual examples of the light (using quality 3.7V 18650 Li-Ion bats of course). « Show Less
1101643
Hello David,The answer is sort of technical, so bare with me. The lumen is the derived unit of luminous flux. Luminous flux is a measure of the total "amount" of visible light (as measured in the green light wavelength spectrum) emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all electromagnetic waves emitted, independent of the eye's ability to perceive it. Lumens are related to lux in that one lux is one lumen per square meter.Check out Wiikipedia for a more complete answer.Thanks, Glen from CampingStuff Hello David,The answer is sort of technical, so bare with me. The lumen is the derived unit of luminous flux. Luminous flux is a measure of the total "amount" of visible light (as measured in the green light wavelength spectrum) emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all electromagnetic waves emitted, independent of the eye's ability to perceive it. Lumens are... » Read More Hello David,The answer is sort of technical, so bare with me. The lumen is the derived unit of luminous flux. Luminous flux is a measure of the total "amount" of visible light (as measured in the green light wavelength spectrum) emitted by a source. Luminous flux differs from power (radiant flux) in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux measurements indicate the total power of all electromagnetic waves emitted, independent of the eye's ability to perceive it. Lumens are related to lux in that one lux is one lumen per square meter.Check out Wiikipedia for a more complete answer.Thanks, Glen from CampingStuff « Show Less
255674
I don't know about lumens exactly, but I measured the output with a light meter and it registers about 15k to 20k lux (1 lux is equal to 1 lumen per square meter, I think). They say 20k lux is legit for growing plants. I ordered 4 different types of grow lights, and this actually has the highest output (including a 60 dollar T5 setup), it just doesn't cover a whole lot of area, although definitely covers more than the other under $20 LED lights. I may buy quite a few of these.
1220724
We used a clf compact fluoresent but any standard screw base normal size 120 volt .lamp should work. That would include incandescents.
1692951
There Website is WWW.UsiElectric.com ; They should be able to send you the list of what the indicator lights mean - the list is long.
754159
The meter measures the amount of light. To the best of my knowledge the light spectrum is not taken into account. I grow orchids in natural day light so I am not an authority on the best way to go with artificial lighting.
892778
No, the meter only reads the real time light intensity in foot candles. You would need multiple readings throughout the day and then estimate an average.
1790322
1500 lux equals approximately 690 lumens at a half meter distance at 90 degrees light incidence...look up a lux to lumens conversion to get a sense of it since it's a function of distance and incident angle...i.e. this lamp is a fine desk lamp for all but the most meticulous of tasks...diff temps n intensities...I like it.
316631
It doesn't list it in Lumens, but this one is 16 Million Candlelight. It's a different form of measurement (like Meters versus Liter). Candlelight measures total light emitted, where as Lumens measures How much light will illuminate the target at a given distance.
1363733
The Technical Specs in the User Manual doesn't list it Lumens; it lists: Range [m /ft]: 100 / 328; Focusable: Yes; Light: Xenon
1210193
The full technical data sheet for this ballast may be found here: http://www.usa.lighting.philips.com/pwc_li/us_en/connect/assets/additional-literature/t8-instant-start-centium/ICN4P32N.pdf The data sheet contains the physical (dimensional) values.
216865
Light Output:High brightness: 350 lumensMedium brightness: 95 lumensLow Brightness: 45 Lumens Runtime:High brightness: Up to 1.75 continuous hoursMedium brightness: Up to 3.50 continuous hoursLow brightness: Up to 6.75 continuous hoursStrobe: Up to 5.50 continuous hours
403068
I grow orchids and use the light meter to monitor how much light they are getting. I do not have any experience as a photographer or in using this meter in that manner. Sorry. Dana
2275301
It reads both but the 2 I received did not work. One only read f4 regardless of how much flash was used and the replacement they sent me did not work at all. I will keep looking for an affordable light meter but will not trust this product. Hope this helps.
471507
For the medical therapy effect the most meningful unit of measure is lux, i.e. the intensity of the light impacting the human skin or ear tissue. Valkee's light intensity in the ear canal is about 10,000 lux, which corresponds with the intensity of big tabloetop bright light lamps that need mains electricity. 10,000 lux is also the required intensity for bright light devices to be approved for medical insurance reimursability in the few countries where it is a reimbursable insudred cost for treating SAD.