Range Extension down to 1 mL/h of Micro Liquid Flow Calibration Facility at CSIR-NPL, India

• Published in: MĀPAN : journal of Metrology Society of India 2024-12, Vol.39 (4), p.955-966
• Main Authors: Sanjeet Kumar, Jaiswal, S. K., Varshney, A., Singh, C., Yadav, S.
• Format: Article
• Language: English
• Subjects: Calibration; Confidence intervals; Distilled water; Evaporation rate; Flow measurement; Flow stability; Flow velocity; Liquid flow; Mathematical and Computational Physics; Mathematical Methods in Physics; Measurement Science and Instrumentation; Mineral oils; Numerical and Computational Physics; Original Paper; Physics; Physics and Astronomy; Reproducibility; Simulation; Syringes; Theoretical
• ISSN: 0970-3950; 0974-9853
• DOI: 10.1007/s12647-024-00768-9

The present paper outlines the efforts for the range extension of the existing CSIR-NPL micro liquid flow calibration facility (having flow range of (10–1500) mL/h) from 10 mL/h  down to 1 mL/h and its metrological assessment. The major challenges in this study are evaporation, flow rate stability and repeatability. To reduce the evaporation, a small quantity of mineral oil was mixed with distilled water in the collection beaker, forming a thin layer of oil over the beaker water surface, leading to reduced evaporation. For improving the flow stability and repeatability, a high-accuracy syringe pump with a 10 mL syringe and a precision balance of 82 g capacity have been used. The static weighing with standing start and standing finish method has been used for flow measurement. The expanded uncertainty (at k  = 2 for approx. 95% confidence level) of the facility is found to be (1.0–0.30) % in the flow range (1–1500) mL/h for both totalized volume and volume flow rate measurements. Thus, CSIR-NPL is now able to maintain NMI status in micro liquid flow measurement.