<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Hi Mark,<br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br>Again, worry about strains introduced into the sensor. At some level, every accelerometer is a strainmeter, so best use manufacturer specs for torque, and demand them if not supplied. Alternately, watch the sensor outputs for offsetting of their baselines as you tighten and stop just short. If that does not supply a tight enough anchor, we better look into the matter and also consider the divot option (extra field pain, I realize). I have had poor results from dabs of epoxy on the legs so won't suggest that. RTV or a thin piece of neoprene might work however.</div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br>Cheers,<br>John<br><br>John R. Evans<br><br><b>Normally at:</b><span class="Apple-tab-span" style="white-space: pre; "><b> </b></span><span class="Apple-tab-span" style="white-space: pre; "><b> </b></span><b>Intermittently at:<br></b>U.S. Geological Survey<span class="Apple-tab-span" style="white-space: pre; "> </span>USGS/ASL<br>345 Middlefield Rd, MS-977<span class="Apple-tab-span" style="white-space: pre; "> </span>P.O. Box 82010<br>Menlo Park CA 94025<span class="Apple-tab-span" style="white-space: pre; "> </span>Albuquerque NM 87198-2010<br>650-329-4753<span class="Apple-tab-span" style="white-space: pre; "> </span>505-846-1793<br><a href="mailto:jrevans@usgs.gov">jrevans@usgs.gov</a><span class="Apple-tab-span" style="white-space: pre; "> </span>Cell: 408-209-6219<br><br>There is no problem so great or grave that it cannot be<br>much diminished by a nice cup of tea. (Bernard-Paul Heroux)<br><br>I got nasty habits; I take tea at three. (Mick Jagger)<br><br></div><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><br><br><br><br><br></div></span></div></span></div></span></div></span></div></span></span>
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<br><div><div>On 17 Jan 2011, at 04:00, <a href="mailto:anss-netops-request@geohazards.usgs.gov">anss-netops-request@geohazards.usgs.gov</a> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Send ANSS-netops mailing list submissions to<br><span class="Apple-tab-span" style="white-space:pre"> </span><a href="mailto:anss-netops@geohazards.usgs.gov">anss-netops@geohazards.usgs.gov</a><br><br>To subscribe or unsubscribe via the World Wide Web, visit<br><span class="Apple-tab-span" style="white-space:pre"> </span>https://geohazards.usgs.gov/mailman/listinfo/anss-netops<br>or, via email, send a message with subject or body 'help' to<br><span class="Apple-tab-span" style="white-space:pre"> </span>anss-netops-request@geohazards.usgs.gov<br><br>You can reach the person managing the list at<br><span class="Apple-tab-span" style="white-space:pre"> </span>anss-netops-owner@geohazards.usgs.gov<br><br>When replying, please edit your Subject line so it is more specific<br>than "Re: Contents of ANSS-netops digest..."<br><br><br>Today's Topics:<br><br> 1. Re: mounting bolts for RT 147-01/3 accelerometer<br> (Mark E. Meremonte)<br><br><br>----------------------------------------------------------------------<br><br>Message: 1<br>Date: Sun, 16 Jan 2011 16:57:36 +0000<br>From: "Mark E. Meremonte" <meremonte@usgs.gov><br>To: Tom Yelin <yelin@ess.washington.edu>,<br><span class="Apple-tab-span" style="white-space:pre"> </span>anss-netops@geohazards.usgs.gov<br>Subject: Re: [ANSS-netops] mounting bolts for RT 147-01/3<br><span class="Apple-tab-span" style="white-space:pre"> </span>accelerometer<br>Message-ID: <OF0D3140B9.99061058-ON8725781A.005D2A81@usgs.gov><br>Content-Type: text/plain; charset="us-ascii"; Format="flowed"<br><br>Hi Tom,<br><br>This is the same problem with the new Compact-Trilliums. Nanometrics <br>used a 1/4" x 20 thread/bolt instead of tight, fitting machine <br>threads. (I presume to cut costs) Thus the tightening-disk is more <br>important than before to stabilize the seismometer. Thus rotating <br>the tightening-disk against the base of the C-Trill needs to be very <br>firm and they supply a wrench to do this where before a good strong <br>finger tight was good. However, because the seismometer is <br>light-weight (2.5 lbs) it is easy to push it off its <br>orientation/position even on a rough surface.<br><br>Mark<br><br><br>At 18:26 1/14/2011, Tom Yelin wrote:<br><br><blockquote type="cite">The OEM mounting/restraining bolts for these units have about<br></blockquote><blockquote type="cite">1-2mm play when inserted through the hole in the unit's chassis.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Paul Bodin and I are concerned that even with the nut<br></blockquote><blockquote type="cite">tightened, in the case of large ground motions there will be<br></blockquote><blockquote type="cite">an increased chance that the unit will shift (albeit<br></blockquote><blockquote type="cite">not my much) relative to the mounting point.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">The hole appears to be just shy of 12 mm in diameter.<br></blockquote><blockquote type="cite">Has anyone been concerned enough about this issue<br></blockquote><blockquote type="cite">to find an alternate bolt? If so, do you have<br></blockquote><blockquote type="cite">the size on record, and perhaps a supplier, too?<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Sorry, but I am inherently lazy and trying to avoid<br></blockquote><blockquote type="cite">a trip to the local fastener store.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Tom<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">----------------------------------------------------------<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Mailing Address:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Tom Yelin, U.S. Geological Survey<br></blockquote><blockquote type="cite">c/o University of Washington<br></blockquote><blockquote type="cite">Dept of Earth & Space Sciences<br></blockquote><blockquote type="cite">Box 351310<br></blockquote><blockquote type="cite">Seattle, WA 98195-1310<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Shipping Address:<br></blockquote><blockquote type="cite">(For UPS, FedEx and other services that<br></blockquote><blockquote type="cite">do not accept box numbers)<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Tom Yelin<br></blockquote><blockquote type="cite">University of Washington<br></blockquote><blockquote type="cite">Dept. of Earth & Space Sciences<br></blockquote><blockquote type="cite">70 Johnson Hall<br></blockquote><blockquote type="cite">Seattle, WA 98195-1310<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Phone: 206-553-1937<br></blockquote><blockquote type="cite">Fax: 206-553-8350<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">email: yelin@ess.washington.edu<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">-------------------------------------------------------------<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">_______________________________________________<br></blockquote><blockquote type="cite">ANSS-netops mailing list<br></blockquote><blockquote type="cite">ANSS-netops@geohazards.usgs.gov<br></blockquote><blockquote type="cite">https://geohazards.usgs.gov/mailman/listinfo/anss-netops<br></blockquote><br><br>*********************************************************<br>Mark E. Meremonte Geophysicist USGS/ANSS/NEIC<br><br>U.S. Geological Survey Work: 303-273-8670 Cell: 303-478-5766<br>MS 966, Box 25046 Email: meremonte@usgs.gov<br>Denver, CO 80225 Web: http://geohazards.cr.usgs.gov<br><br>Ship: U.S. Geological Survey, 1711 Illinois St., Golden, CO 80401<br>**********************************************************<br>-------------- next part --------------<br>An HTML attachment was scrubbed...<br>URL: <http://geohazards.usgs.gov/pipermail/anss-netops/attachments/20110116/87559988/attachment-0001.html><br><br>------------------------------<br><br>_______________________________________________<br>ANSS-netops mailing list<br>ANSS-netops@geohazards.usgs.gov<br>https://geohazards.usgs.gov/mailman/listinfo/anss-netops<br><br><br>End of ANSS-netops Digest, Vol 25, Issue 2<br>******************************************<br></div></blockquote></div><br></body></html>