I'd find somebody with a sap hydrometer. have them measure a batch of sap with the hydrometer and then adjust your refractometer to read the same brix.
2012: Probably 750 gravity taps and 50 buckets.
600 gal stainless milk tank.
2 - 100 gallon stock tanks
one 30 gal barrel
50 buckets
3' x 10' Waterloo Raised Flue wood fired evaporator w/ open pans.
12" x 20" Filter Canner
Sawmill next to sugarhouse solves my sugarwood problem
Gather with GMC 3500 2wd Pickup w/ 425 gallon Plastic Tank.
Been tapping here in Lyman NH since 1989 but I've been sugaring since 8 years old in 1968.