TY - JOUR
AU - Janeschitz‐Kriegl, H.
AB - A discussion is given of a number of problems concerning the measurements of flow birefringence and an apparatus is described in which the uncertainties arising from these problems are reduced as much as possible. The problems discussed are: diffraction of light in the narrow gap formed by the cylinders; influence of the optical properties of the material of the cylinders; building up of pressure differences in an apparatus with variable width of slit (Kuhn et al.); appearance of a temperature gradient in the rotating apparatus, disturbing the optics of the system. The apparatus built consists of a stationary outer cylinder and a rotating inner cylinder with a narrow gap in between. A narrow pencil of light runs through the gap and parallel to the cylinder axis. The light, which deviates from the pencil due to diffraction followed by reflection at the cylinder walls, is intercepted by an extra slit behind the apparatus. The cylinders are made of dark glass because of its optical properties. The heat generated in the gap due to the gradient of flow is removed by an extra convection current parallel to the axis of the apparatus and therefore perpendicular to the main flow. In this way it is possible to keep the temperature nearly uniform in the gap.
TI - On the technique of measuring flow birefringence
JF - Journal of Polymer Science Part A Polymer Chemistry
DO - 10.1002/pol.1957.1202310317
DA - 1957-01-01
UR - https://www.deepdyve.com/lp/wiley/on-the-technique-of-measuring-flow-birefringence-b0vBfiUSya
SP - 181
EP - 188
VL - 23
IS - 103
DP - DeepDyve
ER -