Robinair Coolant and Battery Refractometer

Last updated date: February 14, 2020

DWYM Score

Robinair Coolant and Battery Refractometer

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We looked at the top Refractometers and dug through the reviews from some of the most popular review sites. Through this analysis, we've determined the best Refractometer you should buy.

Overall Take

In our analysis of 6 expert reviews, the Robnair Robinair Coolant and Battery Refractometer placed 9th when we looked at the top 10 products in the category. For the full ranking, see below.

Editor's Note May 28, 2020:
Checkout The Best Refractometer for a detailed review of all the top refractometers.

Expert Summarized Score
1 expert reviews
User Summarized Score
154 user reviews
Our Favorite Video Reviews
What experts liked
Comes with a variety of helpful accessories like a foam-lined carrying case, a cleaning cloth, and a vial of distilled water to help you calibrate the refractometer. Unlike some other options, the refractometer has both Fahrenheit and Celsius scales for propylene and ethylene. There’s also a scale for battery acid.
- Electro Deal Pro
What experts didn't like
More expensive than many of the other options.
- Electro Deal Pro

From The Manufacturer

Robinair's No. 75240 Coolant and Battery Refractometer is designed for use in measuring the freeze point of propylene or ethylene glycol based cooling systems and for checking the strength of electrolyte solution batteries. This precision instrument features high-quality optics with ultra smooth focusing. Scale range: -60 degrees Fahrenheit to +32 Fahrenheit. This handheld refractometer is a portable, precision optical instrument used for measuring the freeze point of engine coolant and the operating state of battery charging liquid. It is used on transportation vehicles, such as cars, tractors, tanks, ships, etc., which use propylene or ethylene glycol for coolant and sulphuric acid for charging liquid. When a liquid (such as coolant or charging liquid) is placed on the prism, the light passing through it is bent. The more concentrated the liquid, the more the light will bend. The refractometer contains a reticle, or scale, that is enlarged through the eyepiece to measure this bent light. The values of the scale have been established to evaluate the coolant or charging liquid. Complete kit includes refractometer with rugged aluminum housing, eyedropper, screwdriver, vial of distilled water, cleaning cloth, foam lined rigid plastic case, and complete usage instructions. Robinair, a Bosch Automotive Service Solutions brand, is a global leader in service tools and equipment based in Owatonna, Minnesota. Robinair is recognized throughout the world as the quality and performance leader in AC/R evacuation tools and this position has led to its success with the full range of products that serve the heating/ventilating/air conditioning/refrigeration (HVAC-R) and mobile markets, which includes the automotive aftermarket along with other industries such as agriculture and construction.

Overall Product Rankings

Ade Advanced Optics Beer Wort and Wine Refractometer
1. Ade Advanced Optics Beer Wort and Wine Refractometer
Overall Score: 9.6
Expert Reviews: 2
Agriculture Solutions Salinity Refractometer
2. Agriculture Solutions Salinity Refractometer
Overall Score: 9.4
Expert Reviews: 1
Aichose Honey Refractometer
3. Aichose Honey Refractometer
Overall Score: 9.2
Expert Reviews: 1
SMARTSMITH Refractometer Honey
4. SMARTSMITH Refractometer Honey
Overall Score: 9.1
Expert Reviews: 0
Aichose Refractometer for Diesel Engines
5. Aichose Refractometer for Diesel Engines
Overall Score: 9.1
Expert Reviews: 0
SunGrow Aquarium Refractometer with Calibration Tool
6. SunGrow Aquarium Refractometer with Calibration Tool
Overall Score: 9.0
Expert Reviews: 0
AUTOUTLET Salinity Refractometer
8. AUTOUTLET Salinity Refractometer
Overall Score: 8.9
Expert Reviews: 0
Robinair Coolant and Battery Refractometer
9. Robinair Coolant and Battery Refractometer
Overall Score: 8.9
Expert Reviews: 1
Aichose Refractometer with ATC
10. Aichose Refractometer with ATC
Overall Score: 8.4
Expert Reviews: 0

An Overview On Refractometers

Required by people with a few select, niche hobbies or occupations, a refractometer is a unique tool with particular properties. Because of this, making the best choice can be challenging. Before shopping for a refractometer, considering several factors can help you determine what to look for to select the right tool for your needs.

Industry and application are the first considerations to bear in mind. If you are a professional beekeeper who wants to ascertain the best time to harvest honey, a refractometer designed to measure moisture, Brix (the sugar content of the liquid), and Baume (the density of the honey). Alternatively, if you have a saltwater pool, you will need a refractometer that tests the salinity of the water.

Ease of use is another factor to consider. You will appreciate a lightweight, portable device that you can pick up and carry as needed. And a prism that is easy to clean will provide more accurate results.

Prism material can be important, as well. While glass prisms are the most economical, they are not as durable as sapphire prisms, which are four times harder than glass.

DWYM Fun Fact

In 1869, German physicist and optical scientist Ernst Abbé built the first refractometer. Five years later, he published a booklet discussing the use of prisms and total reflection to measure the refractive index of fluids.  Abbé used the device in his work, designing lenses for a German optical manufacturer.

Around the end of WWI, other manufacturers began producing refractometers, which were primarily created for laboratory use.


The Refractometer Buying Guide

  • If you prefer a manual instrument, shop for a transmission-style refractometer. With this device, you place a sample on the prism and align it by turning a control knob.
  • If you prefer an automatic instrument, shop for a reflection-style refractometer. With this device, you place a sample on the prism and press a button to read the measurements.
  • Density is not the only thing that can change the refractive index of a liquid. Temperature can affect it, as well. A high-quality refractometer will feature automatic temperature compensation, sometimes labeled ATC. This feature will provide consistent reports over a range of practical temperatures.
  • Look for a dual-scale refractometer. These instruments report results in both Brix and specific gravity units.