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Name: Hamzath
Status: other
Grade: other
Location: N/A
Country: Sri Lanka
Date: N/A 


Question:
What device is used to measure light concentration?



Replies:
Hi Hamzath,

I believe that when you said "light concentration", you meant "light intensity", or simply, "brightness".

Light intensity is measured in units called "Lux", and measured using a Lux meter. This does not measure the total amount of light being emitted over a large area by a light source, but simply the intensity (or brightness) at any selected point.

The so-called "light meter" that is often built into higher quality film cameras, is a simplified Lux meter and measures the relative inensity of light in order to allow you to set the correct exposure.

Regards,

Bob Wilson


A photometer is used -- although "light concentration" is not a standard scientific term. Typically intensity and flux are the terms used. There are plenty of good resources on the Internet for more detailed reading.

Hope this helps,
Burr Zimmerman


Hamzath

This URL explains light measurement terminology and how the terms are defined. The terms are candle-power, lumens, radiance and illuminance.

http://www.theledlight.com/lumens.html

Light meters are used to measure the concentration of light. This is quite a common tool for photographers so there are many light meters on the market. I "Googled" "Lumen Meter" and you can find many products.

Here is a hand-held meter that reports out lux or foot candles:

http://www.globaltestsupply.com/c/181/Amprobe_Meterman _LM_120_Light_Meter_with_Auto_Ranging.html

Here is a cheaper version:

http://www.globaltestsupply.com/c/181/Amprobe_Meterman _LM100_Light_Meter.html

You can also find other meters, perhaps cheaper, by "Googling" "Light Meter".

You can find the Google search engine at http://www.google.com

So there you are. Good luck.

Sincere regards,
Mike Stewart



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