How to Use a Traditional Analog Handheld Refractometer


Different models of traditional analog refractometers have different internal scales on which to read fluid concentrations. Some instruments have specialized scales that indicate the exact mixture of the sample being tested, while others have an arbitrary unit of measure that works like a shorthand for refractive index measurements.

The instruction manual that comes with each refractometer carefully explains the procedure for comparing refractometer readings to the actual known concentrations or properties of your specific fluid. Trained MISCO technical support engineers are always available to assist you at any time.

How to Take a Reading With a Traditional Analog Refractometer

MISCO refractometers are easy-to-use and require little or no training. They can be mastered by ANYONE in just minutes.

  1. Place a drop of sample on the measuring surface beneath the ViewPoint Illuminator.
  2. Look through eyepiece and press the ViewPoint Illuminator.
  3. Take your reading at the point where the contrast line (difference between light and dark areas) crosses the scale.


How a Traditional Analog Refractometer Works

Light passing through a liquid is slowed compared to the speed it travels in air. So once a fluid sample is placed on the measuring surface of a refractometer, the light passing through it slows and is bent.

The refractometer focuses this bent light on a tiny internal scale. The scale is magnified by the eyepiece lenses so it is easily visible.

The optics are supported by a bi-metal strip that moves lenses in response to temperature changes, ensuring that readings are accurate regardless of temperature.



Fire Protection (8)

I need a refractometer to check Glycerin, and possibly propylene glycol. What handheld palm abbe would be best for me? The PA202 or PA203 Will the PA202 measure glycol? Does the pa203 come with pre-installed scales or custom scales for each use? My application is for antifreeze. Fahrenheit readings please. Please advise.

With the right combination of scales, either the Palm Abbe PA202x or PA203 digital refractometer will handle the job of measuring glycerin and propylene glycol antifreeze solutions. Scales are available to read nearly any physical property of glycerin and propylene glycol, including scales for freeze point and concentration or other units of measure such as specific gravity, density, percent by weight or volume, and more.

Do you have any refractometer that can tell whether an unknown liquid is glycol or glycerin?

No, unfortunately a refractometer cannot tell the difference between glycol and glycerin. Although we do have refractometers with both glycol and glycerin scales, you must know which fluid you are testing and test it on the correct scale to get an accurate measurement of concentration or freeze point.

Hello, I am looking to buy a palm abbe for the purpose of testing glycerine based liquids which model would you recommend?

The MISCO Palm Abbe digital refractometer equipped with a glycerin concentration or freezepoint scale is the simplest and most accurate means of testing glycerin/water solutions. Scales are available for measuring glycerin percent by weight or percent by volume, freeze point, density, or specific gravity.

Category: Fire Protection

Hi, will your hand held (both glycerin/ glycol) read below zero. In Utah we are required to provide -0 readings. Please let me know.

The glycerin scale on the Palm Abbe digital refractometer can measure the freeze point of glycerin from +32 to -46 °F. It can read glycerin concentration from 0 to 100%. The propylene glycol scale for this refractometer can measure propylene glycol freeze point from +32 to -60 °F. It can also read propylene glycol concentration from 0 to 100%.

I was searching for a high quality digital refractometer when came across your company website. Basically the refractometer will be used to check the water to foam ratio of a fire fighters water tank (fire engine). I would appreciate if you suggest a suitable model with high precision and I would like to obtain the price and delivery time.

Our Palm Abbe digital handheld refractometer is ideal for measuring firefighting foam concentration. The Palm Abbe PA202 has a refractive index scale with a precision of +/-0.0001 nD20 (refractive index). For more information, please search our site for PA202.

Category: Fire Protection

Need a refractometer that will read glycerin based antifreeze for fire suppression. Firefight GL is the product we use. Thanks.

You can test both glycerin concentration and freeze point with the Palm Abbe digital refractometer. Model PA202-16-18 has scales for glycerin concentration by volume and glycerin freeze point in degrees Fahrenheit. Other models have scales for both glycerin and propylene glycol. Trying searching for “glycerin” in the Palm Abbe product area to find the refractometer with the scales that you need.


Glycerine- Propylene Glycol Refractometer- Glycerine-; Propylene Glycol Scale-Percent Volume-Freeze Point °C– Digital Refractometer

Glycerine Propylene Glycol Refractometer Glycerine Propylene Glycol Scales  Percent Volume  Freeze Point °F  Digital Refractometer

Glycerine Refractometer ; Glycerine Scales Concentration Freeze Point °C – Digital Refractometer

Glycerine Refractometer Glycerine Scales  Concentration Freeze Point °F-Digital Refractometer

Category: Fire Protection

What is the difference between freezepoint and burst point when testing with a refractometer.

Freezepoint is the point that the first ice crystals form in the absence of supercooling. Burst point is the point that the solution freezes solid and bursts the vessel containing it. The burst point is usually 30-50 degrees colder than the freezepoint. Our Glycol & Battery Tester reads the freezepoint of both ethylene and propylene glycol solutions. If you need to know the burst point, take a reading on the Glycol & Battery Tester and use a chart (available from your antifreeze supplier) to cross-reference freezepoint to burst point or percent concentration.

Please kindly furnish me with information and price on a refractometer for testing airport foam solutions for dealing with aircraft fires. The test we do presently is visual. We would like to upgrade, especially now that we have new Rescue and Fire Fighting Trucks that produce AFFF and FFFP foam solutions. We would like our inspectors to be using it to assess the foam solution concentration, quality and performance.

The best method for measuring AFFF and FFFP fire-fighting foam solutions is with the MISCO Palm Abbe PA202 digital refractometer. The PA202 has a scale for refractive index and a precision of +/- 0.0001 refractive index units, making it ideal for field testing firefighting foam.  Our best device for this is our Brix Refractometer – with Refractive Index measurement. 

Category: Fire Protection