The GMC 320+ that I own is nearing 11 months now and in the past 6 months it has started to exhibit some very troubling issues.
1) When the unit is left on to log data it behaves normally up to day 45 with avg CPM at around 16, but as soon as it reaches day 46 the avg CPM spikes over 500. This unit has done this 3 times in succession the past 135 days after resetting. This leads to issue #2.
2) After resetting the unit it goes into a "boot loop" on power up that lasts 5-10 minutes. This issue has been mentioned in the forums and GQ is attributing it to some sort of "corruption" that the "boot loop" is supposedly clearing.
Is the unit that I have defective and can it be returned for repair or replacement? It is becoming frustrating to have to deal with this problem every month and a half when I bought this unit for long term monitoring.
I have a similar problem with two GMC 300E+s. When I measure high count rates, like 240 CPM (from Thorium), I see a cycle with high and low counts over a period of about 600 seconds. Is there a firmware fix for this, or is 240 CPM too fast for this model? This graph's y axis is in counts per second for two 300E+ models.