<br><font size=2 face="Arial">Sounds like a pretty nice improvement. Depending on cost, I would be interested.</font>
<br>
<br><font size=2 face="Arial">John E. Harlan<br>
Advanced Technology<br>
Abbott Laboratories<br>
Dept. R46Y AP10-2<br>
100 Abbott Park Road, </font>
<br><font size=2 face="Arial">Abbott Park IL 60064-6100<br>
</font>
<br><font size=2 face="Arial">(847) 938-4278 Tel. <br>
(847) 935-4994 Fax<br>
john.e.harlan@abbott.com</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td>
<td><font size=1 face="sans-serif"><b>Walter Stafford <stafford@bbri.org></b></font>
<br><font size=1 face="sans-serif">Sent by: rasmb-admin@server1.bbri.org</font>
<p><font size=1 face="sans-serif">03/11/2005 11:18 AM</font>
<br>
<td><font size=1 face="Arial"> </font>
<br><font size=1 face="sans-serif"> To: rasmb@server1.bbri.org</font>
<br><font size=1 face="sans-serif"> cc: </font>
<br><font size=1 face="sans-serif"> Subject: [RASMB] Elevated temperature operation with a turbomoledcular pump.</font></table>
<br>
<br>
<br><font size=3 face="Times New Roman">Dear RASMB-ers</font>
<br>
<br><font size=3 face="Times New Roman"> I have been testing a turbomolecular pump as a replacement for the standard diffusion pump on the XL-I. I am writing to report the results of that experiment.</font>
<br>
<br><font size=3 face="Times New Roman">On my machine, with the standard diffusion pump installed, I have not been able to run above about 23 degrees without having serious fogging of the interference condensing lens after about 15 minutes, making it impossible to take data.</font>
<br>
<br><font size=3 face="Times New Roman">About a month ago, with the help of the Beckman Serviceman and folks from the Axiden Division of Alcatel Vacuum Technology</font><font size=1 face="Times New Roman"> {http://www.adixen-usa.com/</font><font size=3 face="Times New Roman">}, we installed an ATP80 TMP in place of the diffusion pump. Other than a flange that had to be machined to mate the TMP to the diffusion pump flange, it was a direct replacement. The original rough pump was used to back up the TMP. </font><font size=1 face="Times New Roman"> see: {http://www.adixen.com/all/dyn/products/products.php?id_prod=20&lg=us</font><font size=3 face="Times New Roman">}</font>
<br>
<br><font size=3 face="Times New Roman">So far the results have been quite remarkable. After the first test of running for 4 days at 40 degrees, the optics were clean. The chamber was actually cleaner after the run than before. The TMP seemed to have removed all the residual oil that we were unable to remove after replacing the diffusion pump. It pumps down to 3-5 micons in less than 5 minutes and ultimately to about 1-2 microns. The fringe patterns seem to be more stable (not sure exactly why, but I was informed that the regular diffusion pump heater normally cycles on and off; the flexing associated with that may explain it).</font>
<br>
<br><font size=3 face="Times New Roman">We use it routinely now for all runs and couldn't be happier with it.</font>
<br>
<br><font size=3 face="Times New Roman">Several labs have expressed an interest in installing one on their machines.</font>
<br>
<br><font size=3 face="Times New Roman">However, Beckman will not support the pump or provide one as standard equipment unless there is sufficient interest. A proper, Murphy-proof installation would require a firmware change and field service support to allow it to be included under the service contract and warranty.</font>
<br>
<br><font size=3 face="Times New Roman">I would like to take a survey of those who might be interested, so that we can convey that expression of interest to Beckman.</font>
<br>
<br><font size=3 face="Times New Roman">If you have an interest and think that running at higher than 20 degrees or higher precision might be useful to you, please respond to this email by replying to the RASMB. I'll collect the responses and comments and forward them to the folks at Beckman.</font>
<br>
<br><font size=3 face="Times New Roman">It has opened new vistas for our research.</font>
<br>
<br><font size=3 face="Times New Roman">Thanks</font>
<br><font size=3 face="Times New Roman">Walter</font>
<br><font size=3 face="Courier New">-- <br>
</font>
<br><font size=3 color=#0b0963 face="Times New Roman">########################################################################</font>
<br><font size=3 color=#0b0963 face="Times New Roman">Walter F. Stafford III, Ph.D.</font>
<br><font size=3 color=#0b0963 face="Times New Roman">Analytical Ultracentrifugation Research Laboratory<br>
Senior Scientist<br>
Boston Biomedical Research Institute<br>
64 Grove Street<br>
Watertown, MA 02472-2829<br>
<br>
main:(617) 926-8040<br>
tel: (617) 658-7808<br>
fax: (617) 972-1753<br>
<br>
mailto:stafford@bbri.org</font>
<br><font size=3 color=#0b0963 face="Times New Roman">http://www.bbri.org/faculty/stafford/Stafford.html</font>
<br><font size=3 color=#0b0963 face="Times New Roman">#################################################################</font>
<br>
<br>