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.



Other Food & Beverage (10)

Can your digital refractometer be used to determine balling (sugars) in distillers mash? The standard has been to use a balling hydrometer. Also would there be one to determine alcohol in the fermenting mash? The max is around 9% by volume.

Our Palm Abbe digital refractometer is ideal for measuring the sugar content of mash for beer makers. You can use either the Brix scale or the balling scale for this. Once fermentation begins a refractometer cannot be used to “directly’ measure either the sugar content or the ethanol content since they will interfere with each other. However, there are some indirect methods using the Brix scale to monitor fermentation.

What are all the different salt scales used for? I need to measure salinity content but don’t know what scale I need.

Chemically, salts are ionic compounds that result from the neutralization reaction of an acid and a base. There are several varieties of salts containing chlorides, acetates, fluorides, and sulfates. The most common salt is sodium chloride (NaCl) or regular table salt. Although we have a refractometer scale that will measure most common salts, we also have an extensive list of scales for sodium chloride. You may select from scales for measuring sodium chloride concentration in percent by weight, specific gravity, freeze point, parts per thousand (ppt), g/100g, density, percent saturation, and even Baume. The most common units of measure are percent by weight, percent saturation, and freeze point. The scale that is correct for you depend on what unit of measure you are most interested in. Multiple salt scales can be programed into the MISCO Palm Abbe digital refractometer so you can just change between different units of measure as your needs change. MISCO also has scales available for the salinity of seawater.

Hi, I just bought the Palm Abbe refractometer with 5 scales from you. I have tried it at our office but I cannot get it come to the right results. We are only going to measure total sugar content and alcohol in wines (finished wines). I have calibrated it with distilled water and it seems to measure water to 0.0 every time which is ok. As soon as i measure alcohol in red wine it always shows too high digits – up to 18-20% ABV and the sugar is always too high. What may the problem be in this case?

The problem is that you cannot directly measure the alcohol content in finished wine using a refractometer. Once fermentation begins ethanol and the residual sugar interfere with each other and prevent an accurate reading of either sugar content or alcohol content. The best method for determining the alcohol content in the wine is distillation. There are also some good methods of estimating alcohol and sugar content during fermentation and later in the finished wine. For more information, download a copy of our free guide, “Using Refractometers to Increase the Efficiency of Vineyard Management and Winemaking “Using Refractometers to Increase the Efficiency of Vineyard Management and Winemaking.”

We are a small winery on premise in Michigan and we make our wines from Must and kits only, we don’t crush the grapes. Is there a refractometer you could recommend for our purposes which could tell us actual specific gravity and Actual Alcohol readings of finished wine?

A refractometer is very useful at nearly all stages of wine production. It can be used to help assess the ripeness of grapes before harvest, predict alcohol content from the must, measure the sugar content of must, monitor the fermentation process, and determine the alcohol by volume (ABV) of the finished wine. A refractometer with the Brix scale is the best method of determining the sugar concentration of the grapes and must. Scales are available that can predict the alcohol content of the finished wine based on must measurements. Once fermentation begins ethanol will interfere with sugar readings and you will not be able to take direct readings of either alcohol content or sugar content, without using special techniques. Once the wine is finished, the same refractometer, with an ethanol scale, can be used to measure the distillate of the wine to accurately determine alcohol content.
Click the following link to download a copy of our technical bulletin on “Using Refractometers to Increase the Efficiency of Vineyard Management and Winemaking.”

I am interested in the VIN06 refractometer for the determination of alcohol in fortified wines. What is the process for determining the alcohol – it appears you have to distil the wine before measuring it with the refractometer. How would I do this?

You cannot directly measure the alcohol content in a finished wine with a refractometer. However, you can distil the wine and then use the alcohol scale on the Palm Abbe digital refractometer to measure the ethanol content of the distillate. More information can be found in our technical bulletin  “Using Refractometers to Increase the Efficiency of Vineyard Management and Winemaking.

We are looking for a Quantitative Determination of Sucralose, in order to control the dosing accurately. Please tell me is there any solution.

Thank you for your question. The best method of measuring Sucralose and Splenda is with the Palm Abbe digital refractometer. Scales are available for this refractometer to accurately measure the concentration of both Sucralose (0 to 28% w/w) and Splenda (0 to 45 % w/w) with a resolution of 0.1%.

Product : Splenda-Sucralose Digital Refractometer

Full question

We just purchased a MISCO digital salometer for measuring sodium chloride concentration. We have a process that needs to mix DI water with Sodium Chloride (NaCl) to 100% saturation. I am hoping that the meter I have bought is the correct version for this job?

The MISCO Digital Salometer is a refractometer that measures the percent saturation of sodium chloride (NaCl) salt in water. The refractometer will display the percent saturation of sodium chloride from 0 to 100% as well as display the freeze point of the solution in either Fahrenheit or Celsius (model dependent). A digital Salometer overcomes many of the problems associated with traditional analog Salometers. Traditional Salometers are cumbersome to use and time consuming. They are simply a glass or plastic hydrometer with a special scale that displays degrees SAL instead of specific gravity. In use, the traditional Salometer is floated in a graduated cylinder containing salt brine. The reading is taken at the point at which the surface of the fluid crosses the analog scale divisions; the temperature must then be read with a thermometer, followed by a manual temperature correction of the reading.

There is no method for field calibrating the apparatus; it is difficult to resolve the tiny scale divisions; it must be thoroughly cleaned and dried to prevent salt residue from influencing subsequent readings; and it is easily broken. The MISCO Digital Salometer is much easier to use and much more accurate. Simply place a couple of drops of sodium chloride solution on the measuring surface, close the evaporation cover, and press the button to initiate the readings. The percent saturation is displayed nearly instantly on the large LCD display.


Sodium Chloride Salt Brine Refractometer Salometer,  Sodium Chloride Salt Brine , Percent Saturation , Freeze Point in °C

Sodium Chloride Salt Brine Refractometer Salometer,; Sodium Chloride Salt Brine,; Percent Saturation Freeze Point in °F


We are a California manufacturer of a carbonated low-alcohol beverage and are looking for a relatively low-cost way to test samples to make sure alcohol is below 0.5%. Would your refractometer work for this?

Unless your beverage is just ethanol and water, a refractometer will not be able to directly measure the alcohol content. This is because sugars in the solution will conflict with a reading of alcohol and vice a versa. Probably the best way to test this is by distilling the beverage and measuring the distillate with a Palm Abbe digital refractometer equipped with an ethanol scale.

We use your Palm Abbe PA201 digital refractometer for making sorbet, and love it! But we’re confused as to how it operates on solutions that contain sugar and alcohol in combination: the readings don’t seem to make sense. Is there a way to compensate for this?

Unfortunately it is not possible to measure sugar contents and alcohol content in combination in a sorbet or other solution using a refractometer. Refractometers are very good at measuring binary solutions (two-part), such as water and sugar, where water is a constant and sugar is a variable. However, a refractometer is not very good for measuring multi-component solutions such as water, sugar, and alcohol. When there are several different components in a solution, such as water, sugar, and alcohol, it is difficult to tell what the contribution is that each component makes to the total refractive index. So, if the refractive index changes, it is impossible to say, with any certainty, which of the component parts changed. A refractometer only measures the total refractive index of a solution and cannot selectively read the refractive index of one particular component. All water soluble fluids look the same to the refractometer. So, depending on the concentrations of the other constituents, it may be difficult to get an accurate reading of any one component.

How accurate is your refractometer when alcohol is present? Can I measure R.S. [residual sugar] in wine? thanks

Alcohol and sugar interferes with each other when measuring finished wine with a refractometer. You cannot measure the alcohol content in a finished wine directly using a refractometer, nor can you directly measure the residual sugar content. There are however, a couple of tricks that you can use to determine alcohol content and residual sugar content using a refractometer. These methods and more are discussed in detail in our technical bulletin, “Using Refractometers to Increase the Efficiency of Vineyard Management and Winemaking.