The LR03 refractometer measures the sugar content in a sample of grape must at the time of delivery to the wine processing plant. The washing, rinsing with must and measurement operations have to be realized manually with guidance from the touch screen operator panel. The instrument displays the results in the selected scale and, thanks to a serial output, allows the user to print them or to repeat the measurement or connect up to the processing plant’s management software. The refractometric measurement of the must is direct, extremely repeatable and is not affected by color. Thanks to the vertical prism and prism cleaner, the presence of suspended solids and emulsions in the must do not have any influence on the results. The analysis of approximately 200 ml of must makes the measurement representative of the grape sample taken. The compact size of the instrument means it can easily be transported and positioned to meet all the needs of the winery.