Professional Salinity Refractometer for Aquarium, Saltwater Testing, Dual Scale Salinity Tester 0-100 PPT 1.000-1.070 Specific Gravity Saline Seawater Hydrometer ATC with Calibration Fluid ? DUAL SCALE: Measuring Ranges: 0-100 ppt of Salinity and 1.000 to 1.070 Specific Gravity (0-10%)the reading resolution is 0.1 %. Salinity Accuracy: +/ - 0.1% ? ACCURATE READINGS with ATC: Thanks to the ATC function ( Automatic Temperature Compensation ) you will be able to read accurately the result ? EASY TO USE: Its scale provides a direct reading of the specific gravity and concentration (part per Thousand) of salt in water ? UNIVERSAL FIT: Best for aquariums, marine monitoring, Agricultural, Gardening and Educational Purposes ? PORTABLE and DURABLE: Easy to use, sturdy design, compact in size and light in weight, convenient to keep up and carry around We have been developing and selling this series of instruments for about 10 years, with a very professional team and factory. We've been concentrating to supply constant stable high standard products to customers all over the world. Our products are equipped with high-quality optics and smooth focusing. The main body is made of aluminum alloy. The internal optical lens with a high refractive index makes up the precision optical system. The instrument is resistant to abrasion and corrosion, can be used to measure the salinity of general corrosive liquid. (But we do not recommend measuring these liquids for a long time. The residue should be cleaned immediately after measurement. ) Dual Scale Specific Gravity and PPT. With this refractometer, you can get the result in two different units at the same time in just one test. ATC Function This refractometer is equipped with an automatic temperature compensation function, minimizing the impact of temperature on accuracy. Include Comes with everything you need: a hard case, droppers, a screwdriver, a user manual, and a cleaning cloth. Average Salinity of Sea Water Research shows that the average salinity of sea water is about 35?, of course there are differences between each sea, for example the salinity of Dead Sea is as high as 227?~281?, and the salinity of Baltic Sea is as low as 10?, but for most sea, the salinity is between 30?~35?. So the scale range of this refractometer is perfect for measuring sea water or approximate salinity solution. The Scale Range Dual Scale The scale range of this refractometer is 0~100? ( 1?=1 PPT=1000PPM, PPT means"parts per thousand", PPM means"parts per million"), it also shows the corresponding specific gravity range 1.000 to 1.070. These are the most common units to show the salinity of water. With this refractometer you can get the result in two different ways at the same time in just one test. The min reading resolution is 1 ?, this make it possible to mearsure low concentrated salt solutions. Intended Uses For Marine Monitoring For most sea, the salinity is between 30?~35?. So this refractometer is ideal for simple marine monitoring and research. For Aquariums Water Monitoring Ideal for aquariums or marine fishkeeping amateurs, cause they just need to make the salinity of water similar to the sea water. For Swimming Pool Water Measuring If you use a salt chlorine machine to disinfect your pool, you should make sure the salinity right first, normally the salinity should be between 3?~7?, this refractometer can help. For Lab or Indurstry Purposes Ideal for lab and industry use for testing salinity solution in the range of 0~100?. Digital refractometer, Hydrometers or this kind of Optical Refractometer? Digital refractometer: Normally it's very expensive, but the accuracy is not much better. Traditional hydrometers: More complex to use and the result is not very accurate. This kind of Optical Refractometer: Easy to use, not expensive and good accuracy. Is it complex to use a refractometer? It's easy to use. Calibration: Place a few drops of distilled water on the prism and use the screwdriver to adjust the calibration screw until the reading is"0". Measuring: Place a few drops of solutions you want to test on the prism and look into the eyepiece, you will get the reading. Note: The user manual will show you the details about how to use the instrument exactly, it is very easy to use even for new users. Easy to use. Need no battery.