I just got my GMC - 320 plus and when I place it next to my thoriated mantle, the reading goes up as it should but when it reaches about 6 microsieverts it jumps down to 3 microsieverts and goes up again to 5 where it stops.
I would like to know if I should add up both readings like 6+5=11 microsieverts/h or is the counter just evening the counts out?
//Edit: So I've just noticed that it happens when I hit 1000CPM, can it be some problem with callibration? Like I said I got it few hours ago so it should be calibrated.
Thank you but unfortunately I'm not able to change the values. When I try it directly in the counter, it won't let me go above 32000 and when I set it over terminal in Data viewer it says that it was successfully written into unit but when I click on read from unit, it still shows those defaul values.
You can go over 32000. You have to use -1 which is actually 65534. At least that is what the 300+ shows if you go over 32,767, then the value counts down with a minus in front. I tested it and the negative values are actually values over 32,767.
Could you try if that works with the data viewer? I can't atm.
GMC-300E+ V4.20 with sbt-11 alpha tube
My statements are to be taken as stuff-a-hobbyist-says.
I tried what you've suggested but I was able to get to -4 only for some reason and when I input it over the terminal it still won't change. I've also noticed that every setting I change resets after I turn the unit off and on again.
The firmware version 4.0 or later implemented the safe upgrade via USB mechanism. The V3 upgrade is not easy as V4 and it has chance to lock up the unit if the upgrade fail. Once upgrade fail on V3, the only way to recover is to send the unit back to GQ. Unless you are very good in electronics.