The Hydrometer is a measuring instrument that provide the density (densimeter in °Brix) AND the temperature(thermometer) at the same time. Therefore, you can determine the density of your maple product by interpreting the two red lines visible on the instrument : the density scale has a precision level of 0.2°Brix and the correction scale (adjustment) displays the temperature with a precision of 0.1°C. To use it, make sure that the Hydrometer is clean and dry. Insert it slowly in the hydrometer cup and note the density visible (ex. : 66°Brix). The correction is visible on the other line (ex. : +0.2). You can now extrapolate the precise density by adding both data : 66°Brix + 0.2°C = 66.2°Brix. To store the Hydrometer, make sure it is kept in a standing position to avoir red line separation.