Measuring Range (nD) : 1.32000~1.58000
Temperature Control : Peltier Thermostat 5 – 75℃



・Compact Size Benchtop Refractometer (Built-in Temperature Control )

Space-saving of A4 Size, Two-thirds of Previous Models in Size (192mm×281mm)(Comparison with previous models.)
Half of previous models in weight with aluminum die casting housing.
Can be installed anywhere in a limited space of lab.

・Easy to Clean Sample Stage

Easy operation with sample stage at the front.

・Sample Cover Equipped with Anti Volatilization Device

Anti Volatilization Device
Furnished on back side of sample cover to prevent sample liquid from volatilizing.
Splash Prevention
Sample cover, when opened, prevents sample from being splashed on LCD.
Secure Measurement
Start button will not be activated when sample cover remains open.

  • Graphic indicator to grasp concentration range


Type Refractometer
Model RA-620
Measuring Method Detection of Critical Angle of Optical Refraction
Light Source LED Na-D Line (589.3nm)
Measuring Items Refractive Index, Brix, Other Concentrations
Measuring Range Refractive Index (nD) : 1.32000 - 1.58000
Brix : 0.00 ~ 100.00%
Accuracy*1 Refractive Index (nD) : ±0.00002
Brix : ±0.014% *2 (0 ~ 85.0%)
Repeatability*3 Refractive Index (nD) : ±0.00001
Brix : 0.01%
Resolution Refractive Index (nD) : 0.00001
Brix : 0.01%
Temperature Control Peltier Thermostat 5 - 75℃ *4
Temperature Indication Resolution 0.01°C
Minimum Amount of Sample 0.2mL
Display 4.7-inch Backlit Colour LCD
Operation Touchscreen (Comes with Stylus.)
Security Password Protection
Data Storage Number of Methods : 100 methods
Measurement Results : 300 data
Calibration Record : 20 data
Check Record : 20 data
External Storage : USB Flash Drive
Temp. Compensation Brix :
5.00 ~ 75.00°C (Automatic compensation by preprogrammed conversion table.)
Concentration By Conversion Table: 100 data
Interfaces LAN :
1 port for personal computer (PC)

USB1.1 :
2 ports (for USB flash drive, A4-size printer, barcode reader, keyboard)

RS-232C :
2 ports (for IDP-100, multiple sample changer)
Ambient Conditions Temperature : 5 - 35°C
Humidity : 85%RH or below (No condensation allowed.)
Power Supply DC24V(Main unit), AC100-240V±10%, 50/60Hz(AC adapter)
Power Consumption Approx. 20W
Dimensions 192(W)×281(D)×166(H)mm
Weight Approx. 5kg
Materials in Contact with Samples Prism: Artificial Sapphire
Sample Stage: SUS316
Expandability Barcode Reader: Reads sample name, measurement conditions, value of standard liquid
PC Software: Data Acquisition Software

*1 : By KEM’s standard measurement conditions.
*2 : From RI accuracy of results.
*3 : By KEM’s standard measurement conditions. Subject to sample properties.
*4 : Lower limit 12°C below ambient.


ASTM D1218 Standard Test Method for Refractive Index and Refractive Dispersion of Hydrocarbon Liquids

ASTM D1569 Standard Test Methods for Detergent Alkylate

ASTM D1992 Standard Guide for Testing Synthetic Plasticizers Used in Rubber

ASTM D2140 Standard Practice for Calculating Carbon-Type Composition of Insulating Oils of Petroleum Origin

ASTM D4056 Standard Test Method for Estimation of Solubility of Water in Hydrocarbon and Aliphatic Ester Lubricants

ASTM D4095 Standard Practice for Use of the Refractometer for Determining Nonvolatile Matter (Total Solids) in Floor Polishes

ASTM D5006 Standard Test Method for Measurement of Fuel System Icing Inhibitors (Ether Type) in Aviation Fuels

European Pharmacopoeia / 2.2.6. REFRACTIVE INDEX

ICUMSA GS4/3-13 The Determination of Refractometric Dry Substance (RDS%) of molasses - Accepted and Very Pure Syrups (Liquid Sugars), Thick Juices and Run-off Syrups - Official

ISO 1743 Glucose syrup — Determination of dry matter content — Refractive index method

OIML R124 Refractometers for the measurement of the sugar content of grape must

United States Pharmacopeia–National Formulary / 31 <831> REFRACTIVE INDEX





■Refractometer RA-620 600.pdf






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