From: pcdhSpamMeSenseless@electrooptical.net   
      
   On 1/12/2014 10:29 AM, haiticare2011@gmail.com wrote:   
   >   
   >>   
   >>   
   >> All kinds of stuff absorbs at 460 nm.  You might try the 578 nm   
   >>   
   >> haemoglobin absorption peak, and compare it against something   
   >> nearby, like 600 nm.   
   >   
   > OK thanks. Please allow me to spell out the reason for the nearby   
   > comparison at 600 nm. Actually, I'm not sure. I note from spectrum   
   > of Hb that the ext. coeff. is less in the red (600), so this would   
   > give a base number of light that is not being absorbed as strongly?   
   > TIA JB   
   >>   
      
   That's more or less the whole point.  Something nearby that will let you   
   take out things other than what you want to measure.   
      
   Cheers   
      
   Phil Hobbs   
      
      
      
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