Novel Modification of Large Water Calibration Facility |
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| Chun-lin Chiang, Yi-lin Ho, Jian-yuan Chen |
- Abstract:
- Traditionally, the method used to determine measurement errors of water meters is the so-called "collection" method, in which the quantity of water passed through the water meter is collected in a vessel. Then the quantity is determined volumetrically or by weighing. Other methods with permitted accuracy levels are also accepted by international standards. Now some types of flow meters have relatively high accuracy and can be used to substitute volume tanks as flow standards for error tests of water meters. A flow laboratory which has the water meter test facility has the largest flow capacity in Taiwan. It adopts “collection” method and "delivering" method for error tests of water meters with nominal size (DN) equal to or less than 300 mm and DN from 400 mm to 2 000 mm respectively. Nevertheless, test facilities which introduced volume tanks and "delivering" method were normally processed of an unstable flow rate because of the reducing of water level in the volume tank during the measurement and then affected the measurement accuracy of tests. This paper describes the modification of the test facility. The "master meter" method was substituted for "collection" method and will had a maximum test meter size up to 800 mm. The maximum test flow rate could be to 4 200 m³/h and the measurement uncertainty was estimated to be 0.2 %. A novel design of a multi-channel flow adaptive control device was provided for improving the flow stability of "delivering" method. It used a number of drains with control valves to adjust the flow during the measurement. The maximum test flow rate could be up to 10 000 m³/h and the maximum test meter size could reach to 1 500 mm.
- Keywords:
- water meter test facility, “collection” method, “delivering” method, “master meter” method, flow rate
- Download:
- IMEKO-TC9-2010-010.pdf
- DOI:
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