Short capillary tubing as fiber optic sensor of viscosity of liquids

Optical capillaries are used in capillary gas and liquid chromatography, capillary electrophoresis, absorbance spectroscopy, Raman spectroscopy etc. These micro-fluidic methods find applications in biotechnologies, medical diagnostic, drug discovery and environmental sciences. In the presented work we discuss some aspects of light guidance in capillary tubing made from silica glass or Teflon AF. The wide range of capillary constructions allows them to be used advantageously in specific applications. We have analyzed both theoretically and experimentally partially liquid filled optical capillaries as fiber optic sensor elements in laser light transmission and reflection conditions at 670, 1310 and 1550 nm. We have shown that the light transmission properties and signal in the reflectometric mode of work depend on capillary construction, their length and position of inserted liquid drop. The results obtained by us show that capillary tubing can be used as sensing elements in optical fiber sensors of surface tension and viscosity of small liquid samples with volume below 10-8 cm3.

[1]  B. Stuart Infrared Spectroscopy , 2004, Analytical Techniques in Forensic Science.

[2]  Zhanfeng Cui,et al.  Enhancing hollow fibre ultrafiltration using slug-flow — a hydrodynamic study , 2002 .

[3]  Hui Fan,et al.  Thermodynamics modeling for moving contact line in gas/liquid/solid system: Capillary rise problem revisited , 2001 .

[4]  M. Borecki,et al.  Light transmission characteristics of silica capillaries , 2006, Symposium on Photonics Applications in Astronomy, Communications, Industry, and High-Energy Physics Experiments (WILGA).

[5]  H Franke,et al.  Water-core waveguide for pollution measurements in the deep ultraviolet. , 1998, Applied optics.