In this work we develop a physical model which describes the behavior of an unsteady flow measured with a gravimetric set up. The model is based on equation for the physical shape of the interfaces between different fluids in the beaker (air-oil and oil-water) and on models of contact angles between these interfaces and the [...]
The aim of this work is to develop a physical model for the thermal processes that occur in the nano-flow generator of VSL, which is based on thermal expansion of water enclosed in a titanium reservoir. The model aims at establishing a numerical model for the flow rate in order to estimate the uncertainties involved. [...]
Within MeDD various primary standards are developed for the calibration of infusion devices and flow meters. These standards, or calibration facilities, have been developed for liquid flow rates at ambient pressure and temperature. The flow rate range per standard varies somewhat; the combined flow rate range is between 1 nl/min up to 10 ml/min. Goal [...]
Defining the regions (1 – 1000) μl/min as microflow and (1 – 1000) nl/min as nanoflow, this white paper describes various principles for a primary realization of the measurement. In this document we briefly describe some common principles for flow rate calibrations. Typically, the gravimetric approach is used for microflow rates. For nanoflow rates potential [...]
The second European Flow Measurement Workshop for ultrasonic flowmeters and Coriolis was held in Sintra from 25-27 March 2014. This event organized by the Dutch Metrology Institute (VSL) and the Colorado Engineering Experiment Station Inc. (CEESI), was attended by about 160 participants. The goal of this event focused on the dissemination of new technologies and [...]
The buoyancy correction is a correction to determine the true mass of an object on a balance if not in vacuum. A rock weighs less under water, and the same goes for weights in air compared to vacuum. When performing buoyancy correction for nanoflow measurement, the buoyancy correction becomes extra complicated, as effects of offset masses, [...]
Within MeDD various primary standards are developed for the calibration of infusion devices and flow meters. These standards, or calibration facilities, have been developed for liquid flow rates at ambient pressure and temperature. The flow rate range per standard varies somewhat; the combined flow rate range is between 1 nl/min up to 10 ml/min. Goal [...]
How would you like if your new syringe pump pumps like this? Here a 60 ml syringe with a rubber based plunger sealing is set to pump 15 ml/h. It takes 4 hours to empty the syringe. The set-up is degassed and has no compliance in the tubing, which otherwise would dampen the flow pulsations. [...]
Calibration and use of syringe pumps, Elsa Batista, Nelson Almeida, Eduarda Filipe, Anselmo Costa, in proceedings of 'Congrès international de métrologie', Paris, France, October 2013. Abstract. There are several types of infusion instruments used for drug delivery, e.g. syringe pumps and infusion pumps, with different capacities according to their use and applied therapeutic. In order to [...]
DTI has evaluated the effectiveness of the oil based evaporation cover to lower than 5000 times compared to uncovered. At this evaporation rate it would take thousands of year for a simple glass of water to evaporate. But the twist is that it actually would gain in weight instead, from the amount of dust and [...]