These scientific portable refractometers work in ambient light with no battery or other power source necessary. They can be used in labs, on production lines, in the field, or anywhere. Simply place a drop or two of sample on the prism and read the results immediately. With reasonable care their reliability, precision, and optical performance will last forever. All North Coast refractometers come complete with: 


North Coast salinity refractometers are designed for testing the concentration of salt water and brine. A triple scale provides a direct reading of the specific gravity and concentration (Parts per Thousand) of salt in water. It provides reliable refractive index and salinity readings of total dissolved solids of aqueous solutions. It is used for quality control in research and clinical laboratories and can be used to check and maintain stock solutions and dilutions. In the food industry, it is especially effective in the preparation of frozen vegetables, fruits, seafood and ocean by-products. The Salinity Refractometer is also used in oceanography and seawater studies for determining soil quality. All of our models offered feature ATC (Automatic Temperature Compensation) which is ideal for field use. Automatic Temperature Compensation: when temperature of product sample varies from 68°F (20°C), readings are automatically adjusted to compensate for temperature variance between 50°F to 86°F (10°C to 30°C).


Think about it... you have hundreds, thousands even tens of thousands of invested in your marine tank, yet you probably rely on a $10 box type hydrometer.  Chances are, the hydrometer is not accurate, sometimes not even close. A salinity refractometer is the only way to accurately measure salinity and specific gravity. All of our salinity refractometers have ATC - Automatic Temperature Compensation: when the temperature of the product sample varies from 68°F (20°C), readings are automatically adjusted to compensate for temperature variance between 50°F to 86°F (10°C to 30°C).

Reads 0-10% salt and 1.000-1.070 specific gravity.

To check salinity- simply place 2-3 drops of tank water on the meter and look at the reading through the eyepiece.

To calibrate- place 2-3 drops of R.O. or distilled water on the meter, look through the eyepiece and turn the calibration screw until the scale reads 0.


Studies have shown that calibrating refractometers with R.O/D.I. water isn't as accurate as we thought.

North Coast Pets now offers 35ppt Refractometer Claibration Solution.

Simply place a few drops on the refractometer prism and calibrate to 35 ppt (1.0264 SG).

2 oz Bottle

NOW ONLY $9.99



Model RHS10ATC
salinity refractometer rhs10atc

Refractometer hinge pinHeavy duty hinge pin design

Refractometer screen

Improved prism design for easier viewing

No screwdriver needed for calibration (thumbscrew adjustment)


Automatic Temperature Compensation

Measures 0-10% and 1.000-1.070 specific gravity

Minimum division- 1% - 0.001 specific gravity
Accurate to 1 division

NOW ONLY $69.99

NOW ONLY $79.99


Model RHS28

Product Specs

* Ranges: 0-28% Salinity
* Accuracy: +/- 1 Division
* Divisions: 0.2%
* Sturdy design


Designed for testing the concentration of salt water and brine. Scale provides a direct reading of the concentration (%) of salt in water from 0-28%. The RHS28 proves itself invaluable for agriculture, food processing and wildlife management. This instrument is  ideal for field use.



NOW ONLY $64.99


Model RHC-200ATC

Urine Specific Gravity:
* Range 1.00-1.050 SG
* Minimum Division: 0.005 SG
* Accuracy: +/1 0.005 SG

Serum Protein:
* Range: 0-12 g/dl
* Minimum Division: 0.20 g/dl
* Accuracy: +/1 0.20 g/dl

Refractive Index:
* Range: 1.330-1.360 RI
* Minimum Division: 0.0005 RI
* Accuracy: 0.0005 RI

RHC-200ATC tri-scale portable Clinical Refractometer in a blue, foam-lined hard case. The RHC series of portable refractometers is designed to measure Urine Specific Gravity, Blood Plasma Serum Protein and Refractive Index. One scale checks Blood Plasma Serum Protein with the range of 0-12 g/dl, another checks for Urine Specific Gravity with a range of 1.000 to 1.050 and the last scale gauges Refractive Index with a range of 1.330 to 1.360 (divisions of 0.2 ppt or 0.005 Specific Gravity) . Models with the “ATC” suffix are equipped with “Automatic Temperature Compensation” for accurate measurements without re-calibration after shifts in ambient working temperature (field use).

Refractometer clinical screen

Included are: a pipette for dropping test fluids onto the prism (never dip the refractometer into the test fluid!), a mini screwdriver for scale calibration, and a Users Guide in a blue plastic, foam-lined hard case.

NOW ONLY $59.99

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