C Scope Refractometer

C Scope
  • C Scope
  • C Scope

What’s Wrong with my Hydrometer?

Many hobbyists are frustrated with traditional swing-arm hydrometers that give inconsistent readings and only provide general guidelines for true salinity & specific gravity.

If you’ve experienced any of these typical concerns associated with hydrometers, it may be time to learn about the benefits of a C Scope Refractometer.

  • Bubbles getting trapped onto the swing-arm
  • Swing-arms that stick
  • Getting different readings from the same test sample
  • Worried that it can’t be re-calibrated

One of the most important parameters when keeping a marine tank is the salinity (salt concentrations) of your water. Natural sea water has a salinity of about 35 ppt (Parts per Thousand).

Monitoring the salt level should be accurate & precise to ensure a safe and optimal environment for tank inhabitants.


Magnified Dual Scale

This simple integrated feature magnifies the scale over 2x compared to traditional refractometers for easy viewing.

ATC - Automatic Temperature Compensation

Since water temperature effects salt readings, all C Scope Refractometers are equipped with ATC to give the correct reading even if your water temperature isn’t.

Accurate & Precise

The C Scope Refractometer will not only deliver the most accurate readings, it will do so consistently with the same test sample.

Quick Calibration

The ability to calibrate the refractometer allows you to cross reference your readings without ever have to second guess yourself.

Deep Color Contrast

The C Scope Refractometer was designed to provide a clear and sharp dual scale. This is accomplished with a deep color contrast between the blue and white to quickly distinguish your measurement.


The C Scope Refractometer is designed for testing the concentrations of saltwater by providing a direct
reading of the specific gravity and salinity in ppt.

It provides a reliable refractive index and salinity readings of total dissolved solids of aqueous solutions. The refractive index is the ratio of the the speed of light in a vacuum to the speed of light in the medium (saltwater) being measured. Light is slowed by passing through saltwater, so the index of the refraction is an indication of this speed change.

You simply add a few drops of your saltwater water over the prism and focus the eyepiece under direct lighting until you see a line that divides the scale from blue and white. This line indicates the specific gravity and the salinity. Clean off the prism and store. We recommend calibrating the refractometer before your next use. This tool will provide many years of TRUE readings, a must for all hobbyists!

Items Include