| Popis: |
Microflow measurement devices are used in several science and health applications, mainly drug delivery. In the last decade, several new methods based on optical technology were developed, namely the front tracking and interferometric method, in which the knowledge of the inner diameter of the syringe or the capillary used is critical. There are only a very few National Metrology Institutes (NMIs) that can perform diameter measurements below 10 mm, which needs very expensive technology. Therefore, the Volume and Flow Laboratory (LVC) of the Portuguese Institute for Quality (IPQ), in cooperation with CETIAT, CMI and the Department of Mechanical and Industrial Engineering (DEMI) of The New University of Lisbon, under the EMPIR project MeDDII, developed new measurement methods for small inner diameters tubes based on the gravimetric principle and optical methods. The gravimetric experimental setup consists of measuring the liquid volume on a specific length of the glass tube. Knowing these two quantities it is possible to determine the inner diameter of a capillary or syringe. The optical method used is based on the front track principle that uses a high-resolution camera and ImageJ software, to determine the diameter at both ends of each capillary. To validate the developed methods, a comparison was made between CETIAT, CMI and IPQ. This work allows the determination of inner diameter of syringes or capillaries used in microflow measurements applications with relative expanded uncertainties in the order from 0,1% to 0,5% (k=2). |
