Peter wrote: >> standard requires that a field at each point in a 0.5m matrix be within 6 dB of an empirically identified reference node - except:
CONCESSION 1 On p14, Note 2 says that "calibration requirements are fulfilled if a maximum of 3% of the frequencies does not meet the 6dB criterion but are at least within the tolerance of -0 to +10 dB. CONCESSION 2 On p15, "i) stop the procedure if at least 12 numbers are within 6dB". I have an array of readings of forward power required to create a constant field at each frequency step at each point in the grid. The answer is different depending on the order in which the concessions are applied. Can someone please translate the requirements into a process that I can apply to data in an Excel spreadsheet? << Hi, Peter. My understanding is that at least 12 out of the 16 points must normally be -0 to +6 dB. Thus, the test for that frequency stops (Concession 2) when this has been met, and one proceeds to the next frequency. However, per Concession 1, if not all 12 points make it, some being up to +10 dB (but not <-0dB), testing continues and at the end of the test, if 3 percent or fewer of the frequencies tested have points up to +10 dB, uniformity may still be claimed. A simple procedure would be to 1. Store each frequency's 16 point scan on one worksheet page and 2. Evaluate them against a -0 to +10dB limit, discarding any outside that range. Stop if you can't get 12 inside this limit; you have some work to do on the chamber. 3. Reevaluate for -0 to +6dB and if 12 points are found, mark the page compliant and go to the next frequency. If you can't get 12 in the -0 to +6dB range then flag the worksheet page and continue to the next frequency. Assuming one percent steps, there are 347 one-percent steps in an 80 to 2500 MHz scan so, if the number of flagged pages is 10 or less, then 4. Continue, stopping only if 5. 11 or more frequencies are flagged, 6. Or the test is done. Cortland Richmond This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Ron Pickard: [email protected] Scott Douglas [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
