20 kHz Magnetic Field Emission of Induction Cooking Heaters

Abstract

Overview

This study investigates the magnetic field leakage produced by induction cooking heaters (IH). Using the finite element method, measurements of magnetic field amplitude were taken at varying distances from the IH, utilizing different types and numbers of pans (two S-type, one S-type, one L-type). The results were compared with ICNIRP limits for general public exposure to 20 kHz magnetic fields.

Findings

• Magnetic field measurements were carried out on four IH models from four manufacturers at a fundamental frequency of 20kHz.
• Magnetic flux densities were measured and reported in microtesla (μT), with the maximum value observed being 16 μT at manufacturer A's device (two S-type pans, X = Z = 0, Y = -20 cm).
• The amount of field leakage depended on pan size and configuration, with the most leakage observed from the basic model (two S-type pans), followed by one S-type pan, and two L-type pans.
• The analysis using the finite element method was validated by close agreement with experimental measurements.

Conclusion

This research clarifies how pan size and arrangement influence magnetic field leakage from induction cookers, providing important information for estimating magnetic field exposure in domestic and workplace environments. Notably, these findings indicate potential health risks due to differing levels of electromagnetic field exposure—especially since some values approach or may exceed certain safety thresholds. Understanding these exposure levels is crucial for supporting safety guidelines and public health.