Digital Wine Refractometer WM-7 The WM-7 with 7 scales is a pocket Digital Wine Refractometer designed to operate of under the strictest environmental conditions, especially areas of high humidity of production and to measure concentration of grape must, easily, speedily, and accurately. Measurement of grape must concentration can be taken by winegrowers, wine cooperatives,wineries, buyers for grape must and so on. The measurement accuracy is upgraded to Brix ± 0.1%. Equipped with a new technology "External-Light-Interference" ( E. L.I. )* that enable you to take accurate measurements with ease and confidence near at a window or outside. *Patent Pending Model WM-7 Cat.No. 3415 Measurement Range ( for 7 scales ) Brix ( determined by ICUMSA ) : 0.0 to 45.0% T.A. 1990 ( Titre Alcoometrique established in 1990 ) : 0.0 to 26.0% T.A. 1971 ( Titre Alcoometrique established in 1971 ) : 0.0 to 25.0% Oe ( GER ) ( Oechsle used in Germany ) : 0 to 240° Oe ( Oechsle ) : 0 to 240° KMW ( or babo ) : 0.0 to 40.0° Baume : 0.0 to 21.0° Minimum Indication Brix ( determined by ICUMSA ) : 0.1% T.A. 1990 ( Titre Alcoometrique established in 1990 ) : 0.1% T.A. 1971 ( Titre Alcoometrique established in 1971 ) : 0.1% Oe ( GER ) ( Oechsle used in Germany ) : 1° Oe ( Oechsle ) : 1° KMW ( or babo ) : 0.1° Baume : 0.1° Measurement Accuracy Brix ( determined by ICUMSA ) : ± 0.1% T.A. 1990 ( Titre Alcoometrique established in 1990 ) : ± 0.2% T.A. 1971 ( Titre Alcoometrique established in 1971 ) : ± 0.2% Oe ( GER ) ( Oechsle used in Germany ) : ± 1° Oe ( Oechsle ) : ± 1° KMW ( or babo ) : ± 0.2° Baume : ± 0.2° Measurement Time 3 seconds Measurement Temperature 5 to 40°C (Automatic Temperature Compensation ) Ambient Temperature 10 to 40°C Power Supply 006P dry battery ( 9V ) International Protection class IP64 Dust-tight and Protected against splashing water. Dimensions & Weight 17×9×4cm, 300g (Main Unit only) Optional * Calibration Certificate : Contact an ATAGO representative for details.