The Bellingham and Stanley D7 polarimeter from Xylem is a manually operated, low cost instrument for measuring the rotation of optically active samples using the variable half wave plate effect. A pair of polarisers are aligned with one rotatable in respect to the other, rotation being measured upon a divided circle. Scale: 0 to 360°A in 1°A increments and International Sugar Scale (ISS): -30° to +130°Z in 1°Z increments. A micrometer drum gives further direct reading to 0.05°A and sugar scale 0.1°Z ISS. Accepts polarimeter tubes up to 220mm in length. A built-in, LED light source and interference filter with intensity control replaces the need for a separate sodium lamp. Overall 320 x 180 x 460mm H x W x D. Weight 5.5kg. Supplied with one 200mm long sample tube, dust cover, instructions and power supply for the light source requiring a 90-230V 50/60Hz single phase supply.