If it is a Part 18 device the lab is probably misapplying FCC 15.31 (f)(2), which gives a 40 dB/decade factor. Part 18 is 20 dB, unless multiple distances are used as Tom pointed out below.
Thanks, [ElementSignature] [cid:image554720.jpg@6ED1BEFC.58F12BBE] David Schaefer​ Technical Manager Element Materials Technology 9349 W Broadway Ave Brooklyn Park , MN 55445 , United States O +1 612 638 5136<tel:+1%20612%20638%205136> ext. 10461 david.schae...@element.com<mailto:david.schae...@element.com> www.element.com<https://www.element.com/> [cid:image983657.png@DC718E95.05F05B18]<https://www.linkedin.com/organization-guest/company/element-materials-technology?challengeId=AQFf9AemZ4SobwAAAXOQwivOsnkHiTt2ByoCkOxVQjOGOjRlivicVgYlN1dz5QXjId9bpa0keWzfVxhl8KPj78uD6-S6nfqRsg&submissionId=e49e0dc0-96a3-2516-27fa-ee2e8c42b177> [cid:image698196.png@7D96A5AB.F2367110]<https://twitter.com/ElementTesting/> [cid:image550308.png@FCD23B9A.39C32D82]<https://www.instagram.com/elementtesting/> [cid:image638143.png@C80615E4.4AE55610]<https://www.youtube.com/c/ElementTesting> [cid:image931709.jpg@79D4D5C5.2D6103DE]<https://elementmaterials.eu.qualtrics.com/jfe/form/SV_3xQqm84s6IydI5D> From: T.Sato [mailto:vef00...@nifty.com] Sent: Wednesday, April 5, 2023 10:14 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] Question for FCC Part 18 RE test? CAUTION:This email originated from outside of Element Materials Technology. DO NOT click links or open attachments unless you recognize the sender and know the content is safe. Please contact IT Service Desk if you are in any doubt about this email. On Thu, 6 Apr 2023 11:32:20 +0900, Youngsik Kim <fs741fs...@gmail.com<mailto:fs741fs...@gmail.com>> wrote: > According to FCC part 18.305 FIELD STRENGTH LIMITS, a test article of Any > type unless otherwise specified has a measurement distance of 300 meters, > but I want to measure it at a distance of 3 meters because I need to > measure it in a chamber. > In this case, what is the limit at 3 meters? > > If we use Any non-ISM frequency, the measurement distance is 300 meters and > the limit value is 15 uV/m, We have a limit of 63.5 dBuV/m when measuring > at 3 meters. > However, other laboratories apply a limit of 103.5 dBuV/m. > Depending on the RF power of the test device, can I use a 40 log instead of > a 20 log conversion? > Is the conversion different depending on the power of the test device? See note 2 in the section, which says: Testing for compliance with these limits may be made at closer distances, provided a sufficient number of measurements are taken to plot the radiation pattern, to determine the major lobes of radiation, and to determine the expected field strength level at 30, 300, or 1600 meters. Alternatively, if measurements are made at only one closer fixed distance, then the permissible field strength limits shall be adjusted using 1/d as an attenuation factor. With the former method above, attenuation factor larger than -20 dB/decade may be used if measurements at closer distances justified that. Regards, Tom - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org<mailto:emc-p...@ieee.org>> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html<http://www.ieee-pses.org/emc-pstc.html> Website: http://www.ieee-pses.org/<http://www.ieee-pses.org> Instructions: http://www.ieee-pses.org/list.html<http://www.ieee-pses.org/list.html> (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html<http://www.ieee-pses.org/listrules.html> For help, send mail to the list administrators: Mike Cantwell <mcantw...@ieee.org<mailto:mcantw...@ieee.org>> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org<mailto:j.bac...@ieee.org>> David Heald: <dhe...@gmail.com<mailto:dhe...@gmail.com>> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1<https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1> Disclaimer This email is sent on behalf of Element Materials Technology Group Limited or the relevant group company with which you are dealing (together, Element). Element Materials Technology Group Limited is a limited company registered in England and Wales with registered number 09915743. Its registered office and its principal place of business is at 3rd Floor, Davidson Building, 5 Southampton Street, London, United Kingdom, WC2E 7HA. Element cannot accept responsibility for any loss or damage sustained as a result of viruses or malware and the recipient must ensure that the email and attachments are virus and malware free. Emails and attachments are opened at your own risk. The information transferred is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Transmission of this email is not intended to waive confidentiality and/or privilege. The contents of this email are subject to contract and do not contain an offer that is capable of acceptance. Unless otherwise agreed in writing with you, the Element Standard Terms of Business for the relevant group company apply in respect of any services provided to you, including advice given to you by email. The Standard Terms of Business are available on request and can be found at https://www.element.com/terms/terms-and-conditions For information about how we process data and monitor communications please see our Privacy statement at https://www.element.com/terms/privacy-statement - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com> _________________________________________________ To unsubscribe from the EMC-PSTC list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=EMC-PSTC&A=1
