Hello Brian, The expected product environment is what should be used when making this type of decision. If the components will be affected by metallic dust or powdered chemicals, many manufacturers coat the circuit board, and some use filters. Temperature also plays a role. The filter restricts the air flow and requires a person to change it periodically. In the old days in the Bell System, we would add an optional filter to equipment when it was installed in places like cement plants, steel works, printing firms, etc., etc. I do not think you will find a specific requirement written regarding the addition of a filter, but I am only going from memory.
Don Don Robert House, MTS Product Certification & Regulatory Compliance Excelsus Technologies, Inc. 2875 Loker Avenue East Carlsbad, CA 92008-6626 USA (760) 918-2552 Office/Lab (760) 476-1519 FAX URL: http://www.excelsus-tech.com -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, September 21, 2000 9:36 AM To: [email protected] Subject: Air filters Can somebody answer this simple question: Under what circumstances, if any, are you obliged to have an air filter in your product ? What standard and clause(s) specify this requirement ? Brian McAuliffe Tellabs
