Hi David, Two quick tidbits came to mind.
1. Many products with fans use thermostats or thermistors to control the fans. In these products, the fans are only turned on when a certain internal temperature is reached. So, there probably is a good justification for measuring the noise at the max rated temperature in order to ensure that you record a maximum noise level. 2. I'm not surprised hear that the standard allows you to rate the product at room temperature and then take an "informational" measurement at max rated temperature. I have seen instances in other ETSI standards (ETS 300 386-1 for EMC) where the standard asks for a test to be performed with no pass/fail criteria and the results to simply be documented for the user. Stay compliant my man! Chris Maxwell Design Engineer NetTest 6 Rhoads Drive, Building 4 Utica,NY 13502 email: chris.maxw...@gnnettest.com phone: 315-266-5128 fax: 315-797-8024 > -----Original Message----- > From: David Heald [SMTP:davehe...@mediaone.net] > Sent: Monday, May 07, 2001 2:10 PM > To: emc-p...@majordomo.ieee.org > Subject: ETSI telecom acoustic power test (fan noise, etc...) > > > Greetings everyone, > I was wondering if anyone has already worked this out. The test > under question measures the sound power level generated by fan trays or > other noise producing structures in Central Office type telecom > equipment. > ETS 300 753 Acoustic noise test calls for the test to be carried out > under 23+-2 deg C ambient conditions. Apparently the results from this > test are the "official" results from which one would derive a rating for > the product. The standard then asks that the test be repeated at the > maximum operating temperature (i.e. 50 deg C). > Is this second test at elevated ambient for informational purposes > only or does it factor into the rated sound power level for the > product? > > Thanks in advance for any help > Dave Heald > > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.rcic.com/ click on "Virtual Conference Hall,"
