Return-Path: Received: from mtain-mb02.r1000.mx.aol.com (mtain-mb02.r1000.mx.aol.com [172.29.96.22]) by air-dd02.mail.aol.com (v128.1) with ESMTP id MAILINDD021-86084bb48ada2d7; Thu, 01 Apr 2010 08:00:26 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 77CAB38000083; Thu, 1 Apr 2010 08:00:24 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NxJ3U-0005lw-Me for rs_out_1@blacksheep.org; Thu, 01 Apr 2010 12:59:24 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NxJ3U-0005ln-C1 for rsgb_lf_group@blacksheep.org; Thu, 01 Apr 2010 12:59:24 +0100 Received: from smtp-vbr7.xs4all.nl ([194.109.24.27]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NxJ3S-0005We-MV for rsgb_lf_group@blacksheep.org; Thu, 01 Apr 2010 12:59:24 +0100 Received: from pc1 (ndb.demon.nl [82.161.81.65]) by smtp-vbr7.xs4all.nl (8.13.8/8.13.8) with ESMTP id o31BxFeq014963 for ; Thu, 1 Apr 2010 13:59:21 +0200 (CEST) (envelope-from roelof@ndb.demon.nl) To: rsgb_lf_group@blacksheep.org References: Date: Thu, 01 Apr 2010 11:59:12 -0000 MIME-Version: 1.0 From: "Roelof Bakker" Message-ID: In-Reply-To: User-Agent: Opera Mail/10.51 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Subject: Re: LF: E-Field Probe calibration question Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G x-aol-sid: 3039ac1d60164bb48ad83b16 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Hello Andy, You could mount the probe at various heights above the car and see how the measured values agree with the calculated values. The bottom of the car forms a capacitor to ground. My guess is that this capacitance is large enough to let the probe "see" a ground that does not significant differ from real ground. But this is just guessing. I have tried to use the body of a car as an E-field probe, but this did not work very well due to the afore mentioned capacitance to ground. Best regards, Roelof Bakker, pa0rdt