BI-RIVS – Refractive Index

The BI-RIVS is a combination RI and Viscometry detector used in SEC/GPC determinations of the MWD using universal calibration.

A true Dual-Detector, refractometer, and viscometer, the only one of its kind available. The refractometer is an integral component of the viscometer bridge, measurement of concentration AND viscosity takes place on the exact same sample segment, at the very same time. Compared to the more common “external” connection of the two detectors, the BI-RIVS Dual-Detector provides a factor of 2 to 5 higher sensitivity, near ZERO delay volume, and unsurpassed overall performance.

There is no need to wait for the sample “breakthrough” (the negative signal you can expect after each injection) or to adapt an “internal delay” to the number of columns you use like other viscometer designs require. The Dual-Detector will match any application you might think of, with any solvent, at any temperature up to 80°C.

The use of a viscometer within a GPC/SEC system requires a source of a concentration signal to complete the necessary calculations. The difficulty is that the DRI Detector, which is usually utilized for this task, must deliver a corresponding concentration signal for each point on the viscosity curve. This is possible with two separate instruments, however precision of the results will be limited due to the volume difference of the detectors. A combo instrument, where both detectors are integral parts of each other, overcomes these limitations and allows a much better determination of the sample under investigation.