VENTURI METERS CONSTRUCTED WITH PIPE FITTINGS: AN UNDER-APPRECIATED OPTION FOR MEASURING AGRICULTURALWATER

摘要

Increasing competition for limited water supplies, improved technology for managing water delivery systems, and a growing importance in being able to document use of water supplies are all factors driving interest in establishing the capability to measure flow at an expanded number of locations in agricultural water delivery systems. Pipe Venturi meters are widely recognized as a measurement technology in piped systems offering a high degree of accuracy while imposing comparatively small head loss. Researchers at the Agricultural Research Service have documented their efforts in using off-the-shelf PVC fittings to produce "constructed Venturi meters" as a low-cost option for measuring water in agricultural systems. These devices can achieve an accuracy on the order of ±2% for a cost of about $ 180. Despite many attractive attributes of this flow measurement concept, this technology has seen a limited degree of adoption. This paper examines field installations where constructed Venturi meters havebeen used to measure flows over a range of magnitudes and under a variety of data collection methodologies using a case study format. Guidelines for construction and installation are also presented.