Deltec Refractometer High Grade

Deltec Refractometer High Grade Almost all, if not all, of the refractometers currently available to the aquarium hobby are designed for measuring saltwater (sodium chloride or brine solution) and not true seawater.Although seawater is mostly sodium chloride it also contains other elements such as magnesium and calcium that change the refractive index slightly and will give a slightly different result. The most common symptom of this differencein refractive index can be seen when mixing up salt as per salt manufacturers instructions and achieving a solution strengthwhere it appears, through testing,that the levels of elements are lower than stated by the manufacturer.In actual fact all of the levels are low as the salinity is not as high as the aquarist believes we have all seen low Ca or Mg for a given SG with almost all brands of salt. It turns out that a 35ppt solution of true seawater has the same refractive index as a 36.5ppt solution of brine and so when using a brine/salt refractometer the salinity is likely to be low by 1.5ppt. This can be allowed for by the aquarist but only if they are aware of the difference. Features: True calibration for Seawater measurement.A New finer scale running from 20-40ppt salinity (SG 1.015 - 1.030)20/20 calibration at room temperature for more consistency and accuracy in everyday use.Full ATC (auto temperature compensation) ranging from 5 to 30 deg C