- This topic has 7 replies, 3 voices, and was last updated 9 years, 9 months ago by SamH.
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December 17, 2014 at 8:57 pm #971Paul.PParticipant
Hi all I’ve been watching #12000029 since it came online .
Its dose rate has been rising slowly over the last 72 hours.
Is this the normal rate for Paisley and is it in a freezer ? have a look at the temp 🙂
I know Scotland can be cold 0.06 C but that’s weird is the temp sensor ok?
just curious- This topic was modified 9 years, 9 months ago by uRADMonitor.
- This topic was modified 9 years, 9 months ago by uRADMonitor.
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December 18, 2014 at 12:55 pm #978uRADMonitorKeymasterThe 12000029 is experiencing a ” time dilatation” problem. As weird as it seems, this is what is happening: the quartz crystal responsible for accurate time measurement has failed (acting like a 4MHz instead of 8MHz), and needs to be replaced. Because of this what the unit should see as one minute is actually 2.04minutes. The DS18B20 that requires precise time intervals for initialisation is unable to measure temperature and shows -0.06. The CPM is double, as radiation is measured across a 2.04minutes interval. The duty cycle is half of what it should be.
Hopefully the unit will be fixed soon and get back online. For the moment I turned it off from the server side.
This was one of the strangest bugs to track as the quartz crystals only rarely fail like this.
- This reply was modified 9 years, 9 months ago by uRADMonitor.
- This reply was modified 9 years, 9 months ago by uRADMonitor.
December 18, 2014 at 2:06 pm #984Paul.PParticipantHi Radu, I think I need to lie down for a while.
When I was reading your reply I kept hearing a stressed out Mr Scot from Star Trek in my head and I sure it was the dilithium crystals not the quarts crystals
that were causing the ” time dilatation ” problem.:-)Thanks for the explanation.
It should be a easy fix to pop out the quarts crystal and have her back online.Cheers
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December 18, 2014 at 6:33 pm #993uRADMonitorKeymasterNice one! 🙂
December 18, 2014 at 6:47 pm #994uRADMonitorKeymasterIndeed the crystal needs to be replaced, as a quick fix to get the unit back online.
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December 18, 2014 at 7:13 pm #998SamHParticipantHi there,
I’m the host of #12000029 and was also concerned about the readings! I was planning on e-mailing Radu, however he was already on it and diagnosed the fault as the 8Mhz crystal – I’ve now ordered up a replacement and will hopefully have a correctly functioning uRADMonitor within a few days.
Hoping the background radiation isn’t as high as previously reported and also that the temp stabilises once the repair is complete.
December 18, 2014 at 10:06 pm #1001Paul.PParticipantGreetings Sam,
just back from my lie down.
I too am glad to see it was a unit fault and not high radiation levels.
But knowing how crazy all my Scottish friends are I did think you might have put the unit in the freezer to run some kind of a wee experiment. 🙂
Fair play to Radu for preempting your email too.
I guess he likes to keep an eye on all his baby’s ahum sorry units.
It will be a doddle of a fix for you to do.
Just 2 solder points and she’ll be tickety-boo.Best regards
Paul #11000038December 27, 2014 at 1:05 pm #1031SamHParticipantA quick update everyone – I replaced the 8Mhz crystal yesterday, it was a fairly straightforward task, although I did have to use a combination of a solder sucker & de-soldering wick to get the faulty crystal out as it was in fairly tight – Installation of a new crystal took less than a minute afterwards.
The good news is that #12000029 is back online – Radu has checked the data it is reporting and all appears to be ok with the dose rate and temperature.
I’ll keep it in my lab in the garage for a couple of weeks under testing then install it outside (when the Scottish weather permits!)
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