Validation of a Microflow Calibration System based on a Weighing Method with Pneumatic Control |
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| Chin Hsia, Cheng-Tsair Yang, Jiunn-Haur Shaw |
- Abstract:
- To calibrate micro flow sensors and as well flow controllers for liquid handling in bio-medicine diagnoses, a traceable system that considers a weighing approach, virtual piston approach, and a velocity-based approach was proposed at CMS. Firstly, a pneumatic push-and-pull pressure control mechanism for steadily driving fluid was verified and estimated of its measurement uncertainty. The capability of the system depends on weighting of the collection bag, the stability of pressure difference, the time interval and the variation of ambient temperature. Due to the low flowrate, weight of collected fluid was measured within a time interval that was pre-determined to keep required accuracy and uncertainty from potential environmental influences. Tests of liquid flow in channels of different dimensions showed that the present system can measure flowrate from 0.1 mL/min to approximately 10 mL/min with an uncertainty < 1.8 %. Deviation of repeated measurements indicated feasibility of the estimation; and comparison with commercial micro liquid sensors indicated practicability of the weighing method.
- Keywords:
- Micro flowrate, Gravimetric analysis, Uncertainty analysis
- Download:
- IMEKO-TC9-2004-032.pdf
- DOI:
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