Independent control of fluid is important for small volume fluid applications including separation science techniques and analytical microchip devices. To effectively control fluid, a monitoring system is necessary to ensure proper response to the control input. Proof of principle for a new online technique for flow monitoring is demonstrated here. It offers near real-time measurements of small-volume flows in a noninvasive, simple, and robust design. The measurement is accomplished by the introduction of a plug of heat into the fluid and detection of the time of its appearance a short distance downstream. Using heat indexing and laser induced interferometric backscatter as the detector, flow monitoring is demonstrated in 184-μm diameter capillary tubing over a range of 2-25 cm/s (500 nL/s to 7 mL/s.).
ASJC Scopus subject areas
- Analytical Chemistry