gravity target

Hello homebrewers, I was wondering if anyone has tried any automated way of measuring gravity during boiling stage? I often have to do adjustments to my water level before I cool the wort for fermentation to get the right pre-fermentation gravity. I usually take a sample, cool it down to ~25...

Okay. i have a must of something or the other... naturally it is 1.010 gravity.... i want 1.100 before yeast pitch according to people on the interweb .039 points per pound or 453.592 grams of sugar (let me know if im wrong) is there is magic equation to find out how much sugar is needed to...