Dual detector

The Combo-One viscometer/DRI detector from Testa Analytical aims to set a new standard for demanding GPC/SEC applications such as those focused on investigating the structure and branching of polymers.

Viscometry detectors for GPC/SEC, based on four matched capillary tubes arranged in a manner analogous to a Wheatstone bridge, have been around for decades but have operational and performance shortfalls. Carlo Dessy, developer of the Combo-One, said: “By eliminating the fundamental drawback of the traditional online viscometer design, the known ‘sample breakthrough’ after each measurement, our dual detector allows much more rapid sequencing of samples. The result of our design innovation is to increase the total daily throughput of a GPC/SEC system by a factor of two. An additional benefit of eliminating ‘sample breakthrough’ is a significant reduction of solvent required for each measurement and consequently the amount of waste produced.”

He added: “Another benefit of our detector is its high sensitivity and resolution. This is achieved as our differential refractometer is an integral part of the viscometer, therefore both concentration and viscosity are measured at the same time on the very same sample segment. When branching calculations and structure investigations are the goal of your GPC/SEC analysis, then resolution and sensitivity are the most important parameters users must optimize for useful results.”

The new viscometer/DRI detector is fully compatible with all modern GPC/SEC systems.


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