Description: The Milwaukee Digital Seawater Refractometer is fast and easy-to-use with a response time under 2 seconds. Maintenance is a breeze with an easy-to-clean sealed flint glass prism and stainless steel well. Ideal for determining the salinity of natural and artificial seawater, ocean water or brackish intermediates. Accuracy: ±2 PSU | ±2 ppt | ±0.002 S.G. (20/20) | ±0.3°C / ±0.5°F Temperature Compensation: Automatic Design features: Fast, accurate results with digital dual level LCD readout Easy measurement with just 2-3 drops of sample needed and results less than 2 seconds Automatically temperature compensated Simple one-point calibration using distilled or deionized water Easy to clean, stainless steel sample well with unit rated to IP65 as "dust tight" and protected against water jets Battery percent level indicator with automatic shut-off (batteries included)Hard plastic case sold separate: MA800.