The CALDON LEFM 880 Series Hydroelectric Ultrasonic Flow Meter system provides extremely accurate and reliable flow measurement for large pipes, hydroelectric penstocks, and open channels. This flowmeter system consists of electronics and transducers, and each transmitter is designed to operate with up to eight pairs of transducers to allow optimized velocity profile integration in various hydraulic conduits.
The CALDON LEFM 880 Series Hydroelectric Ultrasonic Flow Meter incorporates several state-of-the-art features that offer significant improvements in reliability, accuracy, and data management over competitive systems. For example, it has an integral display and digital and analog output capability, and the NEMA 4/IP 66 enclosure is designed for rugged or remote applications.
Transit-time Flow Meters rely on accurate timing of ultrasonic signals transmitted between pairs of transducers. The advanced signal processing techniques used in the CALDON LEFM 880 Series Hydroelectric Ultrasonic Flow Meter greatly extend the operating range of the flowmeter in applications with solids, aeration, or ray bending. In addition, the CALDON LEFM 880 Series Hydroelectric Ultrasonic Flow Meter uses a cross-correlation method to improve signal-to-noise ratios. The system also uses an automatic gain control (AGC) and zero-crossing detection to provide the highest possible timing accuracy.
The Flow Meter's internal processing is optimized to allow measurements up to 50 Hz. This provides dramatically improved signal and data processing.
LEFM 880 Flow Meters utilize deviation and median filters to eliminate data errors and provide smooth outputs. These techniques offer improved performance and faster response to actual flow changes compared to less sophisticated averaging and rate-of-change of velocity of flow filters.
The CALDON LEFM 880 Series Hydroelectric Ultrasonic Flow Meter utilizes dual oscillators to maintain long-term accuracy and reliability. This provides a better assurance of timing accuracy than a simple software-driven self-test.