Digital refractometerMETTLER TOLEDO’s wide range of benchtop and portable digital refractometers measure refractive index and other related values, such as, Br... |
Refractometers for All Your Needs
A synonym for quality and innovation, METTLER TOLEDO offers highly accurate benchtop and portable digital refractometers for a wide range of applications. Designed for use in the laboratory, near the production line, or in storage and receiving areas, our instruments are rugged and intuitive. The measured refractive index can be converted into other units for specific applications, such as Brix, HFCS, alcohol %, and more.
  |  |  |
Excellence Refractometers | Standard EasyPlus Refractometers | Portable Refractometers |
Developed for a wide range of applications, Excellence Refractometers allow for workflow automation and can be expanded to multiparameter systems. Measure almost any sample with high reliability and p... | With a remarkably simple user interface, EasyPlus refractometers allow anyone to obtain accurate results in the lab or near the production line. | Made for use in the lab and on-the-go, the portable refractometer is lightweight and easy to use. |
 |  |  |
Automated Refractometry Measurement | Multiparameter System | Refractometry Software |
Save time, reduce costs, and improve operational safety with seamless automation solutions. From simple sampling pumps to heated autosamplers. Increase results repeatability and reliability. | With Multiparameter Systems you can combine and measure refractive index, density, pH, titration and more. Increase data quality and save time by measuring all parameters at once. | Powerful software solutions for refractometry. The paperless operation will ensure data integrity, secure storage and make transcriptions free of errors. Easily review and analyze your data. |
 | ||
Refractometer Accessories and Consumables | ||
Get the most out of your refractometer by complementing it with accessories and consumables. From high tech solutions such as scanners and sensors, to a variety of certified liquid standards and more. | ||
Developed for a wide range of applications, Excellence Refractometers allow for workflow automation and can be expanded to multiparameter systems. Measure almost any sample with high reliability and p...
With a remarkably simple user interface, EasyPlus refractometers allow anyone to obtain accurate results in the lab or near the production line.
Made for use in the lab and on-the-go, the portable refractometer is lightweight and easy to use.
Save time, reduce costs, and improve operational safety with seamless automation solutions. From simple sampling pumps to heated autosamplers. Increase results repeatability and reliability.
With Multiparameter Systems you can combine and measure refractive index, density, pH, titration and more. Increase data quality and save time by measuring all parameters at once.
Powerful software solutions for refractometry. The paperless operation will ensure data integrity, secure storage and make transcriptions free of errors. Easily review and analyze your data.
Get the most out of your refractometer by complementing it with accessories and consumables. From high tech solutions such as scanners and sensors, to a variety of certified liquid standards and more.
Excellence Refractometers
Accurate, Intuitive, and Modular
The Excellence Refractometers measure liquid samples with an accuracy of up to 5 decimal places. The intuitive One Click™ user interface minimizes training and operator influence. Analyses can be started simply by pressing the corresponding product shortcut. The instrument can be expanded to meet any specific need, adding workflow automation solutions, autosamplers or other instruments for multiparameter measurements.
Standard Refractometers
Simple, Rugged, and Trustworthy
The EasyPlus Refractometers offer basic solutions for measurements in the lab or near production, with an accuracy up to 4 decimal places. Fast measurements with automatic temperature control, small sample volumes and minimal operator dependency make METTLER TOLEDO Standard Refractometers essential to managing your daily routines.
Portable Refractometers
Light, Intuitive, and Rugged
The Refracto line is perfect for many applications: from quality control of incoming goods to at-line quality assurance of intermediate products. Receive accurate and precise results within seconds, displayed in the measurement units needed.
Automated Refractive Index Systems
With the Excellence Refractometers, automation of the refractive index measurement workflow leads to more reliable results, increases safety, and prevents errors, reducing the need for operator interaction with the instrument. This saves time, reduces costs and improves operational safety.
Multiparameter Systems
Refractive index and density are frequently determined for the same sample. Our space-saving system enables you to combine an Excellence Density Meter with an Excellence Refractive Index cell to measure both parameters in one go. Further instruments can be connected for simultaneous measurements, e.g. of refractive index, density, pH and color.
Software Solutions
METTLER TOLEDO offers powerful software solutions for refractive index measurement. Paperless operation ensures data integrity, secure storage, and error-free result recording. Data can be reviewed and analyzed easily, and reports are one click away.
Accessories and Consumables
Get the most out of your refractometer by adding specific accessories to enhance your workflow or adapt the instrument to unique applications.
Check your instrument with certified standards to guarantee measurement accuracy.
Services
Explore our Services - Tailored to Fit your Equipment
We support and service your measurement equipment through its entire life-cycle, from installation to preventive maintenance and calibration to equipment repair.
Expertise
Training & Consulting
Training & Consulting
Publications
FAQ
What is a digital refractometer and how does it work?
Select your Question
- What is a digital refractometer??
- How does a digital refractometer work?
- Which instruments are used to measure refractive index of liquids?
- What is the refractive index of water?
- How much sample volume do you need for a digital refractometer?
- How much time do you need to measure a sample with a digital refractometer?
- How do you adjust a digital refractometer?
- Which samples can be measured with digital refractometers?
What is a digital refractometer?
A digital refractometer uses the total reflection method to measure the refractive index or related values of a liquid sample. This measurement is done digitally, reducing operator influence considerably. Accuracy of up to 0.00002 or 0.01% Brix can be reached, with small sample volume (0.5 to 1 mL) and short measuring time (a few seconds).
 |
How does a digital refractometer work?
Digital refractometers use a light-emitting diode, a sapphire prism and a high-resolution optical sensor. The sample is put on the prism and the measurement started. From a certain angle of incidence – the so-called critical angle – the ray of light no longer penetrates the sample but is fully reflected from its surface and is detected by the optical sensor. The refractive index is calculated from this critical angle. In addition, benchtop digital refractometers use a built-in Peltier thermostat to control the temperature of the sample.
 |
1: Light source
2: Prism
3: Sample
4: Optical sensor (CCD)
Which instruments are used to measure refractive index of liquids?
The refractive index of a solution can be measured manually or digitally.
Manual methods like portable optical refractometers and ABBE optical refractometer are widely used for the determination of refractive index and related values, e.g. BRIX°, alcohol %, Baumé, Plato, etc. Although these methods are easy to use and quite inexpensive, they require expertise in every step of the manual operation protocols, which often affects the accuracy and reliability of the results.
Digital Refractometers are available as benchtop and handheld instruments. They measure liquid samples digitally, reducing operator influence considerably.
Compare digital refractometers with manual methods: Comparison of different measuring techniques
 |
What is the refractive index of water?
The refractive index of water is 1.33299 at 20°C. The refractive index of water changes with the temperature, decreasing with increasing temperature (e.g. 1.33061 at 40°C). Note that this is the commonly used refractive index nD, measured with a light of wavelength of 589.3 nm (D-line of sodium).
 |
How much sample volume do you need for a digital refractometer?
For most bench-top refractometers the typical volume is around 0.5 mL for samples with high surface tension and 1mL for samples with low surface tension. As only a few drops are required, the temperatures of the sample and the measuring cell equalize fast and the analysis therefore takes only a short time.
 |
How much time do you need to measure a sample with a digital refractometer?
This depends on the temperature difference between the sample and the measuring cell, as well as on the sample type and the required accuracy of the measurement. This measuring time is typically a few seconds.
How do you adjust a digital refractometer?
Usually refractometers are adjusted with water at a specific measuring temperature. This temperature is controlled with a Peltier element, which can cool down or heat up the measuring cell to a specific temperature (e.g. 20°C). Sometimes, Brix standards are used to adjust a refractometer for the measurement of sugar concentrations. These Brix standards are often produced onsite. Smart BRIX Standard Preparation can be done using a balance and a refractometer connected to the LabX PC software, increasing the accuracy and traceability and eliminating transcription errors.
Learn more about tests and adjustments of a digital refractometer
Which samples can be measured with digital refractometers?
Digital refractometers were originally designed for measuring homogeneous liquids. In reality, many other samples can successfully be measured, such as pasty samples or even foils. These specific samples require some additional accessories, like a press or a foil stamp. Special care has to be taken for volatile samples (where a flow cell is recommended) or non-homogenous samples where the sample must be stirred/homogenized prior to the measurement. This can be done automatically with the in-beaker homogenizing of the InMotion autosampler.
 |
Aug 22, 2019
Sep 26, 2019
Oct 24, 2019
On Demand Webinar
