Refractometers, hand-held, precision, MASTER-S28a
For simple, manual measurement of concentrations and refractive indices of liquids. Hand-held, precision refractometers with focussing eyepiece, soft rubber eyecups (to reduce straylight ingress, also spectacle lenses do not slip off and are not scratched), case and conversion tables. Hand-held refractometers cannot be fitted with a thermostatic controller and so measurements have to be temperature compensated.

Models with extra code M: Basic model
Models with extra code T: with automatic temperature compensation (ATC)
Models with extra code a: with automatic temperature compensation (ATC) and protection class IP65

Specifications
Type MASTER-S28a, for Sodium Chloride
Measuring range:  Sodium chloride 0.0 to 28.0% (0,0 - 28,0 g/100 g) (Automatic Temperature Compensation)
Accuracy: Brix ±0.2% (±0.2 g/100 g)   (10 til 30°C)  
Minimum scale value: Sodium chloride 0.2% (0.2 g/100 g)
Repeatability: ±0.1%
International Protection Class: IP65 (Except eye piece)
Dimensions and weight: 3.2 x 3.4 x 20.3 cm - 105g
Dust-tight and Protected against water jets