Shane Torpey
Active Member
My Asensetek Passport is out of the box about 4 months so I judge to be accurate. Then SQ500 from Apogee overestimates the same light source (a 3500K Cree COB) reading by about 5% (this is within their spec sheet and probably depends on the spectrum you are reading)
There's a promo video for the SQ500 I can't find at them moment but explains it nicely.