Electromagnetic Flow Detection Technology Based on Correlation Theory

Abstract

When the electromagnetic flowmeter (EMF) is applied to the industrial field, the effective flow signal of the electrode output is easily drowned out by the noise under the condition of strong noise and flow rate lower than 0.2 m/s. However the flow signal drowned out in strong noise cannot be measured accurately by traditional electromagnetic flow detection technology, which cannot separate signal and noise effectively. The correlation technology can be applied to select the reference signal with the same regularity as the target signal to separate the target signal and remove the noise. Firstly, researches on the correlation detection and the basic correlation theory of the electromagnetic flowmeter are carried out. Then, the design of the electromagnetic flow measurement system based on the theoretical research is completed. Finally, in order to verify the performance and accuracy of the designed flow measurement system, a test platform for electromagnetic flow detection is set up, and the verification experiments are implemented. The experiment results show that the electromagnetic flow measurement system based on the correlation theory can not only meet the requirements of traditional flow measurement but also have unique advantages in suppression of strong noise interference, slurry flow measurement, and low flow rate measurement.

Keywords

• Correlation detection
• electromagnetic flow measurement
• interference suppression
• lock-in amplification
• weak signal detection