Verdantas Flow Labs (formerly Alden Research Laboratory) was engaged by a confidential client to perform high-precision testing on a suite of 20-inch ultrasonic clamp-on flow meters. These meters are used in industrial systems where accurate flow measurement is essential for maintaining operational efficiency and regulatory compliance.

Testing was conducted at our Allen High Reynolds Number Facility in Holden, Massachusetts. Using the gravimetric method—recognized for its accuracy and traceability to NIST standards—each meter was evaluated under a range of conditions designed to simulate real-world applications. The meters were installed in both carbon steel and PVC pipe configurations, and the piping was rotated to assess performance under upstream/downstream reversals.

The testing protocol included:

• Diverting flow into calibrated weigh tanks to determine actual volume.
• Capturing real-time meter output using a computer-based data acquisition system.
• Varying flow rates across the full operational range, from low to maximum capacity.
• Calculating correction factors for multiple flow planes at 80%, 90%, and 100% of maximum flow.

The results demonstrated exceptional consistency and identified the effects of less-than-ideal upstream piping conditions. Flow measurement uncertainty remained within ±0.10%, meeting the stringent requirements of ASME/ANSI MFC-9M1988. These findings confirmed the meters’ reliability and readiness for deployment in demanding industrial environments.