Liquid acetone requires special handling and pressurized cells to keep it from explosively disassociating. Ammonia also requires pressure vessels and in pure form is incredibly corrosive
So unless you are trained in these techniques just don't even think about doing this Sent from my iPhone On Jan 26, 2013, at 3:57 PM, "J. Forster" <j...@quikus.com> wrote: > You can't be serious. Ammonia gas or liquid is dangerous. > > You can buy calibrated RTDs or rent a quartz thermometer and stay alive. > > YMMV, > > -John > > =============== > > >> Hi >> >> If the intent is to come up with a triple point cell to calibrate your >> thermometer, acetone's triple point (at 178.5K) is a bit low. I still >> think I'd go with ammonia. >> >> Bob >> >> On Jan 26, 2013, at 2:51 PM, Graham / KE9H <time...@austin.rr.com> wrote: >> >>> On 1/26/2013 1:29 PM, Paul Amaranth wrote: >>>>> Message: 4 >>>>> Date: Sat, 26 Jan 2013 16:28:19 +0100 >>>>> From: Fabio Eboli <fabi...@quipo.it> >>>>> To: Discussion of precise time and frequency measurement >>>>> <time-nuts@febo.com> >>>>> Subject: Re: [time-nuts] OT, looking for a good science forum >>>>> Message-ID: <5ef3f142b075fcab38182666a4e50...@quipo.it> >>>>> Content-Type: text/plain; charset=UTF-8; format=flowed >>>>> >>>>> Il 2013-01-26 14:58 Bob Camp ha scritto: >>>>>> Hi >>>>>> >>>>>> Platinum RTD's are a pretty good bet for -80C, they hold up well down >>>>>> there. For calibration, ammonia and acetylene both have triple points >>>>>> in the vicinity. I'd probably try ammonia first, but not for any good >>>>> Doesn't acetylene have a bad habit of dissociate when pure liquid? >>>>> >>>>> Fabio. >>>> Yes, it's normally stored disolved in acetone. It also spontaneously >>>> dissociates >>>> if pressures exceed 15 psig or 30 psi absolute. That could put a real >>>> damper on your day. >>> Just pure acetone works well at dry ice temperatures. We used crushed >>> dry ice >>> in acetone as an alternative when the liquid nitrogen truck was late >>> making its delivery >>> for the cryro lab. >>> >>> --- Graham / KE9H >>> >>> == >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@febo.com >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
