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.



Sugars (10)

Want to purchase an inline refractometer for the measurement of concentration of glucose fructose and fructose, which will give 4-20mA output which can be interfaced to a card.

One of our Inline Process Refractometers would be ideal for measuring the concentration of glucose and fructose in a process fluid. The VIP refractometer has a 4 to 20 mA output so it will be no problem interfacing with a card, PLC, or other controller.

Categories: Food & Beverage, Sugars

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.

We would like to know about a refractometer that can be used for measuring sugar, glucose and fructose. Ours is an inline application.

Nearly any one of our Inline Process Refractometer is ideal for measuring the concentration of sugar, glucose, and fructose in a fluid. Virtually any scale that can be programmed into the Palm Abbe digital refractometer can also be programmed into the VIP inline refractometer. We have scales available for sugar, glucose, and fructose, and well as many other types of sugar.

I have one of your Maple Syrup Palm Abbe refractometers and was wondering if it is possible to add an additional scale for reading invert sugars by percent. And if so how much would it cost for you to add the scale to my device?

Thank you for purchasing the Palm Abbe digital refractometer for measuring maple syrup. You can add additional measurement scales to a Palm Abbe refractometer depending on the base Palm Abbe model that you have. All Palm Abbe refractometers that begin with model # PA201 can only contain a single scale. All Palm Abbe refractometers that begin with model # PA202 can contain up to two scales. All Palm Abbe refractometers that begin with model # PA203 can contain up to five scales. If you send your Palm Abbe refractometer back to us we can reprogram it for a fee. Reprogramming charges apply to scale changes and scale additions. We have several scales for invert sugar.

Categories: Maple Syrup, Sugars

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.”

If the sugar you wish to measure is sucrose, that’s an easy question to answer. The PA201 Palm Abbe digital refractometer is a single scale refractometer that displays readings on the Brix scale from 0 to 56 %. Brix is the equivalent of percent sucrose by weight. If you are measuring another sugar, such as fructose, maltose, dextrose, invert sugar, or different corn syrup blends, including high fructose corn syrup (HFCS), there is a scale available that can be programmed into the Palm Abbe digital refractometer to meet your needs.

Suggested Base Product: Brix Refractometer – MISCO PA201

Categories: Food & Beverage, Sugars

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.

Can you please kindly advise us if your company manufactures a refractometer with a range of 1.3330 – 1.3340 on the standard refractive index scale and/or 0 to 5 on the Brix Scale.

Scales are currently available for the Palm Abbe digital refractometer that can measure EG (ethylene glycol), PG (propylene glycol), TEG (triethylene glycol), DEG (diethylene glycol), MEA (Monoethanolomine), DEA (Diethanolomine), and DGA (Diglycolamine).

Please contact MISCO customer service for details on ordering, or see the Build-Your-Own section of our website.

I am looking for a small, digital refractometer to measure sugar, dextrose, and glucose up to 85 brix in the ice cream manufacturing business. Which is the right model for me?

Providing that the ratio of sugar, dextrose, and glucose in your solution is relatively constant, the Palm Abbe PA202 refractometer can measure Brix up to 85 Brix.

Might we suggest the PA-202 Brix Scale Handheld Refractometer to meet your needs.

Categories: Food & Beverage, Sugars

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.