Review on Ade Advanced Optics RHB 10ATC 1 REFRACTOMETER by Wendell Chapman

I bought this refractometer to measure the sugar content of maple sap. I'm a small manufacturer and didn't want to spend a lot of money monitoring my RO. I tested with 0%, 3% and 8% sugar in water. It was dead as soon as I set the zero properly. The only negative comment I had was that there was no instruction manual but everything else including the dropper and zero screwdriver was in the case. I bought it on sale for around $14 so can't complain. The device makes a solid impression and feels good in the hand.