Abstract

Traceable Response Time Characterization of Flow Devices with Process-Oriented Liquids

Hugo Bissig, Scientific Researcher, Federal Institute of Metrology METAS

Flow calibrations are important in several areas of pharmaceutical, flow chemistry and health care applications where volumetric dosage or delivery at given flow rates are crucial for the process. Not only a calibrated steady flow rate is important, but also a changing flow rate should be measured accurately as the final delivered volume will depend on these accurate flow measurements. Moreover, most of the flow devices are measuring flow rates of pro-cess-oriented liquids and their calibrations are often performed with water as calibration liquid. It is recommended to perform the calibrations of the flow devices with process-oriented liq-uids as the liquid itself might influence the performance of the flow devices. Therefore, the Microflow and Milliflow facilities at METAS have been upgraded to cover these requirements from the microfluidic industry. So far, calibrations for steady and changing flow rates in the range from 100 nl/min up to 400 ml/min with uncertainties from 0.7 % to 0.07 % respective from 3 % to 0.2 % can be realised with process-oriented liquids. The METAS piston provers produce traceable fast changing flow rates within 1 s and allow determining the char-acteristic response time of any flow device.