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The Captive Purity Refractometer is an incredibly accurate and easy to use device that eliminates the confusion associated with inexpensive hydrometers. Just place a couple of drops of water on the prism and hold to the light. Reads in percent and specific gravity. An absolute must for the serious marine hobbyist. The Captive Purity Refractometer is an optical device (no batteries) dual scaled 0-100% specific gravity: 1. 0 to 1. 070. Calibrate with distilled water. Adjustable eyepiece, carrying case, pipette and calibration screw driver included. This model is ATC (automatic temperature compensating).
The re-designed deep six hydrometer with improved calibration and bubble diffuser ensures more accurate readings of your aquarium salt levels. Also includes a built in base so you can rest the hydrometer on a counter top or other flat surface when taking salt readings.
The new digital refractometers are precision optical instruments used for measuring concentrations of substances in aqueous solutions. They work using the principle of light refraction through liquids. When passing light through a liquid, the test result will be calculated by the computer and shown in the digital display.
Milwaukee Digital Refractometer are very simple to use: simply place one drop of your sample in the prism well, and read the results immediately!
Red Sea’s Seawater Refractometer offers exceptional accuracy, for measuring the absolute salinity of seawater at a temperature of 25oC/77 0F.
Most refractometers used within the aquarium hobby are not specifically designed for reef aquariums and use an algorithm for the measurement of brine (NaCl – rather than seawater) and at a temperature of 15oC/59 0F rather than 25oC/77 0F. Thus, a measurement deviation of up to 1.5ppt is possible, which can have a significant adverse effect on coral growth and coloration.
Main features of Red Sea’s Seawater Refractometer include: