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Question 1: (Main question)

I bought a lux meter while understanding very little about how light is measured. I'm hoping to measure the output of a laser in mW. I assume it's possible to do this at least to an accuracy of about 10-20% which is all I need? If so, please could someone help me out with the equation?

The lux meter came with a frequency response graph, so for example if I measure a green laser (532nm) I know that I need to reduce the reading to 95%... But I'm not sure if this is a graph for the sensitivity of the human eye for various frequencies, or if it's the sensor's sensitivity for frequencies. If it's the latter, then I would need a function for the human eye's sensitivity to frequencies to calculate the power of a laser as well!

Thanks!

PS: I've shone a supposed 20mw laser onto the lux meter (green, 532nm) and it reads around 4000 lux - so this the ballpark figure for double checking the equation :)

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# Measuring laser output with Lux meter

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