Calibration is a critical process to ensure measurement accuracy and operational stability in any flow measurement system. For electromagnetic flowmeters, proper calibration guarantees reliable performance and long-term durability.
This guide outlines the step-by-step electromagnetic flowmeter calibration procedure, key precautions, and professional tips to maintain high measurement precision.
1. Perform Preliminary Verification Tests
Before calibration begins, conduct verification tests based on the pipe diameter and flow rate range. Choose an appropriate pump or calibration system that can deliver a stable and controllable flow.
This step ensures that the calibration conditions match real operational parameters and prevent measurement deviation later.
👉 Learn more: How to Choose the Right Electromagnetic Flowmeter
2. Preheat the Flowmeter
After installation, preheat the electromagnetic flowmeter for at least 30 minutes according to the manufacturer’s calibration specifications.
Preheating stabilizes the internal electronics and ensures accurate zero-point calibration, especially when working in environments with temperature fluctuations.
3. Fill the Sensor and Reset to Zero
Before starting the actual calibration, confirm that the sensor tube is fully filled with the calibration medium (usually water). Then:
- Close the downstream valve to stop the flow.
- Perform a zero reset to eliminate offset signals.
Proper zero adjustment ensures the flowmeter starts measurements from a true baseline, which is essential for accuracy during testing.
4. Check the Pipeline System for Leaks
If using a high-level water tank calibration system, carefully inspect the buffer tower and pipeline connections for leaks.
Before starting the test, circulate the calibration medium (typically clean water) through the pipeline for a specified time to remove trapped air and stabilize flow.
Simultaneously, check all seals and joints to ensure there are no leaks, as even minor leakage can cause calibration errors.
5. Adjust Flow Rate Gradually
At the beginning of the test:
- Open the upstream valve first, allowing fluid to enter the system.
- Gradually open the downstream valve after the flowmeter to adjust the flow rate to each calibration point.
This step prevents sudden pressure surges that could damage the flowmeter or affect the accuracy of the readings.
6. Maintain Flow and Temperature Stability
During calibration, flow stability is crucial:
- Maintain flow variation within 1–2% for the instantaneous flow method.
- Allow up to 5% variation for the total flow method.
Additionally, the temperature of the calibration medium should remain stable:
- Temperature fluctuation per point ≤ 1°C
- Overall temperature variation during the test ≤ 5°C
Stable flow and temperature conditions ensure repeatable and traceable results, leading to precise calibration outcomes.
👉 Explore related products: Electromagnetic Flow Meter
7. Verify and Record Calibration Results
Once calibration is completed, compare the measured data with the reference values to determine measurement deviation.
If necessary, make adjustments through the flowmeter’s digital configuration system to align the reading with the reference standard.
Finally, record and store the calibration data for traceability and future verification.
Conclusion
A properly calibrated electromagnetic flowmeter ensures accurate, stable, and repeatable measurements in industrial operations. Following this systematic calibration procedure minimizes errors, enhances reliability, and extends instrument lifespan.
For high-precision and factory-calibrated instruments, explore Aister’s electromagnetic flowmeters, designed for long-term stability and performance.