# Apogee par meter underwater correction factors



## duckhams (Oct 13, 2009)

This should be a sticky!

*AUGUST 2016: *
Apogee PAR meters are subject to an _'immersion effect'_ meaning that the following correction factors need to be added to the standard readings when used underwater:

*MQ-200 *= +7% (reading x 1.07 = reading with immersion effect corrected)

*MQ-500 *= +32% (reading x 1.32 = reading with immersion effect corrected)

https://reefbuilders.com/2016/08/26...ent-is-strongly-impacted-by-immersion-effect/


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## duckhams (Oct 13, 2009)

*UPDATED: *

*Apogee Releases Calculator for Underwater PAR measurements. *

http://www.apogeeinstruments.co.uk/underwater-par-measurements


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