Salinity Refractometer MASTER-S/Millα

The Atago 2491 MASTER-S/Millα (alpha) is a handheld, portable, water-resistant refractometer with a salinity scale that measures in the 0 to 100% range in parts per million, has specific gravity (1.000 to 1.070 ATC) measurement, automatic temperature compensation (ATC), and is housed in an Ingress-Protection (IP)-65 rated polybutylene terephthalate (PBT) plastic body. A salinity refractometer measures the refractive index of a solution in a sample, converts it to seawater concentration in units of percent by weight (% salinity, also known as degrees salinity), and displays the results. Handheld refractometers, sometimes known as salinity meters or concentration meters, are commonly used in the culinary, food and beverage, pharmaceutical, educational, geological, chemical, and ecological industries, and for water-testing applications.

  • Durable against salty samples
  • Displays salinity in parts per million
  • Automatic temperature compensation
  • Water resistant
  • Salinity Refractometer MASTER-S/MillM
  • Salinity Refractometer MASTER-S/Millα






Salinity : 0 to 100‰

Specific gravity : 1.000 to 1.070

(Automatic Temperature Compensation)

Minimum Scale

Salinity : 1‰

Specific gravity : 0.001


Salinity : ±2‰

Specific gravity : ±0.001


Salinity : ±1‰

Specific gravity : ±0.0005


This instrument measures the salinity and specific gravity of seawater, and utilizes a new material that is durable against salty samples, The salinity of seawater is displayed in parts per mill (‰). It is an Automatic Temperature Compensation (ATC) model with water resistant properties (IP65).

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