MuMetal us great when you need a shield that is thin and pretty light. It needs to be hydrogen annealed after you form it etc. and its expensive. However for shielding what you need is a magnetic shunt. If weight isn't a problem (probably isn't if it's a stationary application) the cheap way to get good shielding is cast iron sewer pipe. The thickness is enough that even if its hard magnetically very little flux will get past it. Plus, once it's at temperature it will take a long time to change. It's very heavy but that helps reduce the internal vibration. The styling may be an issue, you might want to make an external housing. Here are some general details: http://www.acipco.com/adip/pipe/flanged/specs.cfm
>Date: Thu, 24 Dec 2009 15:55:23 -0500 >From: Bob Camp <[email protected]> >Subject: Re: [time-nuts] Cheap Rubidium >To: Discussion of precise time and frequency measurement <[email protected]> >Message-ID: <[email protected]> >Content-Type: text/plain; charset=us-ascii >Hi >Every time I've tried the coli thing, field uniformity has become an issue. I'm also not real sure just how stable multi axis mag sensors are. >If I had a bunch of mu metal sitting in the basement I'd certainly use it in the setup. Last time I checked the stuff was not cheap .... >Bob Demian Martin Product Design Services ***************************************** _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
