ATC Portable Refractometer Black

An ATC refractometer (with Automatic Temperature Compensation) is a device used to measure the salinity of water, especially in aquariums. It works by measuring the refractive index of the water, which is how much light bends as it passes through the sample. The ATC feature ensures accurate readings by automatically correcting for temperature fluctuations. These refractometers are preferred over hydrometers for their accuracy and ease of use, requiring only a few drops of water for a reading.