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*

Hi,

Have you checked that the DP heater is firmly touching the DP body? These can work loose and not transmit all the heat across to where it's needed. Pump looks hot, but is running cool.

Also water flow rate for DPs. Bottom cooling tube should be warm, top should be cool, and middle should be just right.

Ron



On 07/07/2011, at 3:20 AM, "Anthony J. Ruth" <[log in to unmask]> wrote:

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> Moderator: Ellery Frahm, [log in to unmask],
> Electron Microprobe Lab, University of Minnesota
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> 
> 
> *
> 
> I think you are right about the thermal sensor on the Diffusion Pump. Yesterday
> we put it in automatic mode and watched it move through the flow chart. The flow
> chart has several loops where rough pumping is done until certain conditions are
> met. It went through the first loop correctly, but did not leave the second loop
> and move onto the third. The first loop was the compressor which worked fine,
> the next loop was to have the rough pump going on the diffusion pump and the
> heater on the diffusion pump turned on. It is supposed to stay in that loop
> until the pirani gauge on the diffusion pump reached a certain current and the
> diffusion pump is hot. We recently recalibrated the pirani gauges so the
> diffusion pump should have reached the desired pressure. After a while, the
> diffusion pump light was still off, and the vacuum system would go back the
> compressor and restart the flow chart. After going through this several times,
> eventually the light for the diffusion pump turned on, but it would still return
> to the compressor after the second loop. We left it in automatic mode for at
> least an hour, and the system never shut down. Later we tried to do the same
> thing by manually moving through the flow chart, but the diffusion pump light
> never came on and the system still shut down after 30 minutes.
> 
> 
> 
> ----- Original Message -----
> From: Ron Rasch <[log in to unmask]>
> Date: Wednesday, July 6, 2011 3:55 am
> Subject: Re: [PROBE-USERS] disabling 30 minute timer
> To: [log in to unmask]
> 
>> Hi,
>> 
>> I don't think your chamber is contaminated as the valves should 
>> have closed when the compressor failed. The RP was just left 
>> isolated and vented, as it should be, and if wired via the probe 
>> would have turned off too.
>> 
>> If the chamber is contaminated with RP oil, I don't think rough 
>> (RP) pumping it for hours or days will help much. You can do this 
>> in manual mode.
>> 
>> It sounds like the thermal sensors on the DPs have failed, and are 
>> sending the wrong signal to the system. It is not uncommon for a 
>> system to go down and take a few other components with it.
>> 
>> Good luck,
>> Ron
>> 
>> 
>> 
>> 
>> On 06/07/2011, at 12:39 PM, "Matthew Beck" 
>> <[log in to unmask]<mailto:[log in to unmask]>> wrote:
>> 
>> JEOL Probe Users Listserver
>> 
>> Moderator: Ellery Frahm, [log in to unmask]<mailto:[log in to unmask]>, 
>> Electron Microprobe Lab, University of Minnesota
>> 
>> Post a message: send your message to 
>> [log in to unmask]<mailto:[log in to unmask]>
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>> 
>> * Hi Ritchie,
>> 
>> I am Anthony's partner in getting the probe functional. The model 
>> is a JXA-733. We have tried running with both the DP on and off. 
>> The DP does get hot when turned on but the system still shuts down 
>> after 30 minutes of continuous operation. We wish to pump 
>> continuously on the system at the advice of our supervisor. The 
>> system originally failed when the compressor failed allowing the 
>> the RP to pump on atmosphere for days on end. This is in turn 
>> caused the RP to fail. It has since been replaced. It is his belief 
>> that the chambers are now inundated with oil vapor and must be 
>> purged through continuous RP pumping.
>> 
>> Best,
>> 
>> Matthew Beck
>> Illinois Institute of Technology
>> 
>> On Tue, Jul 5, 2011 at 1:26 AM, Ritchie Sims 
>> 
> <<mailto:[log in to unmask]>[log in to unmask]<mailto:[log in to unmask]>>
> wrote:
>> JEOL Probe Users Listserver
>> 
>> Moderator: Ellery Frahm, <mailto:[log in to unmask]> 
>> [log in to unmask]<mailto:[log in to unmask]>,Electron Microprobe Lab, 
>> University of Minnesota
>> 
>> Post a message: send your message to 
>> <mailto:[log in to unmask]>
> [log in to unmask]<mailto:[log in to unmask]>
>> 
>> Unsubscribe: send "SIGNOFF PROBEUSERS" to 
>> <mailto:[log in to unmask]>
> [log in to unmask]<mailto:[log in to unmask]>
>> 
>> On-line help and FAQ: <http://probelab.geo.umn.edu/listserver.html> 
>> http://probelab.geo.umn.edu/listserver.html
>> 
>> 
>> *
>> 
>> Are you running it with the DPs switched off and cold?
>> 
>> My 840 switches off if the DPs are not warmed up within 30 minutes, 
>> but I can leave it pumping the cold DPs (this is all using manual 
>> control of the valves, of course) overnight simply by jumping the 
>> warmup (not the overtemp) temperature sensing switches on the DPs.
>> 
>> Maybe your superprobe (which model?) is the same.
>> 
>> 
>> BTW, I'm not sure that it's such a great idea to suck on the cold 
>> DPs for extended periods as I suspect the DP fluid will get 
>> somewhat contaminated with RP oil by backstreaming. But I don't 
>> have any foreline traps, maybe you do.
>> 
>> 
>> cheers
>> Ritchie Sims
>> University of Auckland
>> ________________________________________
>> From: JEOL-Focused Probe Users List 
>> 
> [<mailto:[log in to unmask]>[log in to unmask]<mailto:[log in to unmask]>]
> on behalf of Anthony J. Ruth
> [<mailto:[log in to unmask]>[log in to unmask]<mailto:[log in to unmask]>]
>> Sent: 02 July 2011 03:49
>> To: <mailto:[log in to unmask]> 
>> [log in to unmask]<mailto:[log in to unmask]>Subject: 
>> [PROBE-USERS] disabling 30 minute timer
>> 
>> JEOL Probe Users Listserver
>> 
>> Moderator: Ellery Frahm, <mailto:[log in to unmask]> 
>> [log in to unmask]<mailto:[log in to unmask]>,Electron Microprobe Lab, 
>> University of Minnesota
>> 
>> Post a message: send your message to 
>> <mailto:[log in to unmask]>
> [log in to unmask]<mailto:[log in to unmask]>
>> 
>> Unsubscribe: send "SIGNOFF PROBEUSERS" to 
>> <mailto:[log in to unmask]>
> [log in to unmask]<mailto:[log in to unmask]>
>> 
>> On-line help and FAQ: <http://probelab.geo.umn.edu/listserver.html> 
>> http://probelab.geo.umn.edu/listserver.html
>> 
>> 
>> *
>> 
>> The superprobe I am working on is having vacuum trouble. We need to 
>> run the
>> roughing pump for an extended period of time to reach low vacuum 
>> and turn on the
>> diffusion pump, but there is a timer that turns off the system if 
>> high vacuum is
>> not reached in 30 minutes. How can I disable the timer? I have 
>> tried adjusting
>> the potentiometers on the manual pump control panel so that all 
>> three pressure
>> meters report high vacuum, but it still did not disable the timer.
>> 
>>