What are the practical methods and procedures for on-site calibration of electromagnetic flowmeters?

On-site electromagnetic flowmeter calibration is essential for maintaining long-term stability of LGF series flowmeters. Primary calibration methods include:

• Zero-point verification: Close pipeline valves and check if flowmeter zero output is within ±0.1% range
• Full-scale verification: Use portable ultrasonic flowmeters as reference standards for comparison
• Electrical parameter testing: Measure excitation current, electrode resistance, and insulation resistance
• Signal output verification: Validate 4-20mA output signal linearity and accuracy

Operational procedures include: first record current operating parameters, then perform zero-point and span verification, finally adjust parameters using HART communicators or supervisory software. For HZ-KSLF radar flowmeters and ultrasonic flowmeters, sensor installation angles and measurement distances require verification. Recommended on-site calibration intervals are 6-12 months for optimal performance.