Maple Syrup Refractometer - Maple Syrup Scales °F - Sugar Content 0 to 85 Brix - MISCO eMaple Refractometer The eMaple Digital Maple Syrup Refractometer can be used at the tree tap or tank to measure maple sap The first scale is a conventional Brix scale with a resolution and a precision of +/- 0.1 Brix. It is intended for accurately measuring maple sap or maple syrup with a fluid temperature at or under 30 °C (86 °F). The second scale is a high-temperature scale for testing syrup above 30 °C (86 °F). Although the resolution of the scale is in whole numbers (no decimal), the user will get a stable repeatable reading within +/- 0.5 Brix with every press of the GO button.