Caption: 
Velocity distribution inside the capillary used in experimental setup 2 (Sec. 2.2), determined using standard solutions from the literature (see [375,pp.195-198] or [355,p.197]). The displayed solution is obtained for $\mathrm{d}V/\mathrm{d}t=1.35$\,mL/min, the maximum flow rate used in Sec. 4.1.

Notes: 
[355] Shah, R. & London, A. (1978). Chapter VII - Rectangular ducts. In Shah, R. &
London, A., editors, Laminar Flow Forced Convection in Ducts, pages 196–222.
Academic Press. DOI: https://doi.org/10.1016/B978-0-12-020051-1.50012-7.

[375] Spurk, J. & Aksel, N. (2019). Strömungslehre: Einführung in die Theorie
der Strömungen. Springer Berlin Heidelberg, Berlin, Heidelberg. DOI: https:
//doi.org/10.1007/978-3-662-58764-5.