Induced electric fields in workers near low-frequency induction heating machines

Area of Science:

• Occupational health and safety
• Electromagnetic field (EMF) research
• Industrial hygiene

Background:

• Limited data exists on occupational exposure to induction heating equipment, especially regarding induced quantities in the human body.
• Assessing electromagnetic field exposure is critical for worker safety in industries utilizing induction heating.

Purpose of the Study:

• To investigate occupational exposure to induction heating equipment, specifically an induction furnace and an induction hardening machine.
• To evaluate induced electric fields in a human model exposed to magnetic flux densities above reference levels.
• To validate a spatial averaging algorithm for measured electromagnetic fields.

Main Methods:

• Measurements of magnetic flux density were taken around an induction furnace and an induction hardening machine.
• A human model was positioned at varying distances to assess exposure.
• A previously developed spatial averaging algorithm was applied to new measurement data.
• Induced electric fields were calculated based on measured magnetic flux densities.

Main Results:

• Measured magnetic flux density values exceeded reference levels at certain distances from the equipment.
• Despite high magnetic flux density, the calculated induced electric field in the human model remained below the basic restriction.
• The lower bound of the 0.1 top percentile induced electric field was 0.193 V/m at 30 cm from the induction furnace.

Conclusions:

• Occupational exposure to the investigated induction heating equipment, even at close proximity, results in induced electric fields within established safety limits.
• The findings contribute valuable data to the scarce literature on electromagnetic field exposure from industrial induction heating.
• The study supports the effectiveness of current safety standards for induction heating equipment in protecting workers.