Quote Originally Posted by chem geek View Post
Actually, according to Taylor, you want your back to the sun with the tube in front of you shaded by your body and you looking straight down into the tube. That is strong indirect sunlight which is what they use for calibrating their tubes.
Richard, are you certain about that? A couple of years ago it was posted here that we should FACE the sun to measure and I've been doing it that way since. Of course, more sun would make the dot more visible which would make CYA seem lower than it is, but I haven't had any problem as a result.

Carl