The specific refractive index increment (dn/dc) is one of the values required for the determination of absolute molecular weight with Static Light Scattering (SLS). The importance of this parameter becomes clear when observing the composition of the Debye Constant used for calculations, where the dn/dc is a squared term. As such, a relatively small error in dn/dc will lead to twice the error in molecular weight. It is important to note that the dn/dc value must be obtained at the same wavelength as the Laser used for Light Scattering or a further unknown error will be introduced.
Image Credit: TESTA Analytical Solutions
The HK Series dn/dc Differential Refractometer is a flexible device that may be used in either static or dynamic mode. In static mode, the specific refractive index (dn/dc) of dissolved samples can be easily and precisely determined in just a few minutes. Beneficially, the new system offers a large number of wavelength options enabling precise matching of your light scattering detector laser operating wavelength, thereby ensuring reliable and reproducible results every time. Where the dn/dc value of the sample is already known, the HK Series dn/dc differential refractometer can be used for precise and sensitive concentration determination. The amount of sample used for this can also be easily recollected and therefore utilized for further investigations.
|DRI Cell Angle
|DRI Cell Volume
|Refractive Index Range (n0)
||1.0 to 1.75 n
||Ambient to 80°C
||620 nm, 535 nm or 470 nm, factory set ‡
||BI-DNDCW for Batch Mode measurements
||90-230 V / 65 W
||ca. 10 Kg
|Size (W, H, D)
||188.75 • 357.04 • 184.40 mm
‡ An extensive range of wavelength options is available to perfectly match the laser used in SLS, thus ensuring that users’ results are perfect.