Metal finishing Q&As since 1989

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Electromagnetic Radiation from a Rectifier

I'm in the process of setting up a new anodising shop, and as part of the development approval process have come across the issue of Electromagnetic Radiation (EMR). I know rectifiers produce some EMR, but I have no idea how much. Is there a formula available to calculate the EMR of a rectifier, or are there any books with the required information? If not, can you suggest who I should go to in order to find out a particular rectifier's EMR?

John Reid
Anodising (under construction) - Brisbane, Qld, Australia
2006

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I never cease to be amazed at the things people find to worry about but if you are really concerned---
Any EMR is going to come from the transformer rather than the rectifier. Ask your local transformer manufacturer. The next stop is your electrical supply company; they have hundreds of transformers running at many thousand volts.
If all else fails, try the electrical engineering department of your local university. If they do not have the answer, they may give the problem to a student to measure it.
There are uncountable rectifiers in the world and I have yet to see a gravestone saying "Here lies an anodiser who died of EMR"

Geoff Smith
Hampshire, England
2006

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Geoff,

Thanks for the help. I'll look into those options. As for being concerned about it - I'm not greatly concerned, but the local City Council is. EMR is now considered an environmental pollutant and must be regulated like all the others are.

John Reid
- Brisbane, Qld, Australia
2006

If your city council wants to eliminate EMR, your whole city would be blacked out. No radio, TV, cell phone signals, or high voltage lines. Back to 19th century?

Guillermo Marrufo
Monterrey, NL, Mexico
2006

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There is no "sunset" provision for the armies of government employees and legions of beltway bandits and quasi-private / quasi-public firms now established in the environmental field. It's about employment and campaign contributions, not EMR, so you can count on ever more environmental rules that will give new meaning to the law of diminishing returns :-)

You'll probably find a politically connected firm in your town offering this EMR testing and certification.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006