STX-3 Handheld Refractometer, 0-100‰ SalinityVEE GEE® X-Series Handheld Refractometers are exceptionally simple to operate and provide quick, accurate measurements for the concentration of nearly any aqueous solution.IncludesCarry Case (1 ea.)Plastic Transfer Pipet (1 ea.)Instruction Manual (1 ea.)The STX-3 from VEE GEE is exceptionally simple to operate and provides quick, precise measurements. Users can accurately and easily monitor the salinity level of seawater, ponds, aquariums, fish farms, and holding tanks.Operation consists of placing 1 or 2 drops of sample on the prism, closing the daylight plate over the sample, then looking through the focusable, cushioned-rubber eyepiece for the reading.The STX-3 features the largest, easiest-to-read scale available with clear, sharp figures, screen shading and incredible contrast. This significantly enhances overall precision, even when several different people use the refractometer. The STX-3 also comes with a rubber grip on the body, which blocks the transmission of hand heat to eliminate temperature errors.With an automatic temperature range of 10 to 30°C, the STX-3 can be used in outdoor environments without the need to re-zero. All measurements are automatically compensated to 20°C. If measurement values shift, zeroing the STX-3 is very simple. The patented "Zero Ring" eliminates the hassle of using a separate tool during zero calibration. Simply place a few drops of distilled water on the prism and turn the "Zero Ring" until the scale is zeroed, and secure the setscrew...that's it!The rugged construction of the STX-3 will provide years of reliable use. The optical glass prism is mounted in an all-metal housing which allows the sample and prism to reach temperature equilibrium quickly. The non-roll stand ensures that once the STX-3 is placed on a table or bench top, it won't be prone to roll off the surface.