Brookhaven - Model BI-DNDC -Deflection-Type Refractometer

The BI-DNDC can be set using the front panel controls and read using the LED readout or by an external computer. It includes a microprocessor, which allows user-friendly handling of all functions of the instrument, as well as refractive index and temperature data transfer to a personal computer via a standard serial interface.

Most importantly, the warm-up time for the BI-DNDC is only one hour, much less than other models on the market.

Determination of dn/dc

The dn/dc determination requires calibration of the batch mode instrument with a solvent/solute combination with known dn/dc, typically KCl in water. The calculated constant is not solvent-dependent and may be used for all further measurements. In batch mode, the instrument comes with BI-DNDCW software for use with an external PC. Included with the BI-DNDC instrument is a syringe kit with PEEK™ and Teflon ® tubing, fittings, and syringes.

The sample may be recovered and reconstituted if required. Typically, five or more concentrations, ranging from 0.1 to 10 mg/mL, are recommended. New instrument readings can be performed in a matter of minutes since it only takes ~ 0.5 mL of liquid to flush out the previous sample.

Determination of concentration

In this mode, the BI-DNDC serves as a highly sensitive concentration detector. Even better, with the right wavelength and the BI-MwA, the BI-DNDC becomes part of a system that eliminates GPC/SEC column calibration.

• Cell Angle: 45°
• Cell Volume (Batch Mode): 8 µL
• Dead Volume (Inlet to Cell/Cell to Outlet): GPC Mode Sample Cell: 0.25 µL, GPC Mode Reference Cell: 100 µL
• Batch Mode Sample Cell: 100 µL: Batch Mode Reference Cell: 8 µL
• Measurement Ranges (ΔRIU Full Scale)(GPC mode): 6×10-4, 3×10-4, 1.5×10-4, 7.5×10-5, 3.75×10-5, 1.87×10-5, 9.3×10-6, 4.6×10-6, 2.3×10-6
• no Range: 1.0 to 1.75 RIU
• Sensitivity (GPC Mode): 1.5 ng (Fructose in H2O)
• Noise Level: < 2.5 x 109, ΔRIU, 25 °C
• Temperature Accuracy: ± 0.5 °C
• Temperature Stability: ± 0.01 °C
• Temperature Range: Ambient to 80 °C
• Specify Wavelength: 620 nm, 535 nm or 470 nm, factory set
• Tubing I.D.: GPC Mode Sample Cell: 0.25 mm, GPC Mode reference cell: 0.5 mm; Batch Mode sample cell: 0.5 mm
• Batch Mode Reference Cell: 0.5 mm
• Flow Rate (typical/maximum): 1.0/3.0 mL/min (Analytical Mode), 5.0/12.0 mL/min (Preparation Mode)
• Time Constant: 0.1 to 2 seconds
• Analog Signal Output: 1 and 10 volt bipolar, full scale
• Digital Signal Output: RS-232/COM port
• Software: BI-DNDCW for Batch Mode measurements
• Data Transfer Rate (baud): 4800, 9600, 19200, 38400, 57600, 115200
• Digital Inputs: Flush, Zero, Sync, Error
• Weight: 8 kg
• Size: 160 x 175 x 340, mm
• Certifications: CE Marked