The 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 10 years, 4 months ago by Radu.
• This reply was modified 10 years, 4 months ago by Radu.

Nice one! 🙂

Hi 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.

A 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!)