Digital Differential Refractometer DD-7

This model measures solutions of low concentration up to 2% at an extremely high accuracy level of ±0.005%. It is recommended for such samples as unsweetened tea and surfactants.

2 types of solutions – distilled water as the standard solution and the sample liquid to be measured – are injected into the instrument with syringes.

By using a standard solution other than distilled water, solutions of higher concentration can also be measured.


Model DD-7
Cat.No. 3930
Scale Brix
Method of measurement Differential optical refraction
Measurement Range 0.000 to 2.000% in concentration (for sucrose solution)
It is possible to measure samples with refractive index up to 1.50 (nD) by reference solutuion. (Samples must be low in viscosity.)
Resolution Brix : 0.001%
Measurement Accuracy Brix : ±0.005 (In the case of measurement of sucrose solution (0 to 2%) at 30°C)
Temperature control range Between 5°C and 10°C above ambient temperature; up to 40°C
*Heating only (no cooling)
Ambient Temperature 10 to 30°C
Power Supply AC100V to 240V, 50/60Hz
Dimensions & Weight 36×35×14cm, 6.2kg
(Main Unit only)
Power consumption 50VA
Output terminals • Digital Printer DP-63 or DP-AD (Optional)
• RS-232C


· Digital Printer DP-63 : Cat.No.3118

· Digital printer DP-AD : Cat.No.3123

· 0.25% Sucrose (±0.005%) : RE-11025D

· 0.50% Sucrose (±0.005%) : RE-11050D

· 1.00% Sucrose (±0.005%) : RE-11100D

· Low concentration Optional Sucrose Solutions below 2.000% (±0.005%) : RE-172030


· Printer paper (regular) : RE-8412

· Printer paper (long-term storage) : RE-8414

· Printer paper : RE-89403

· Ribbon cassette : RE-89402