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Shonky
United Kingdom
1 Posts |
 Posted - 09/21/2025 : 05:34:03
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Hi I'm new here, great forum.
I just bought my first geiger counter, a second hand GMC-300s from fleabay and there's something going on which doesn't make sense.
I'm getting background readings mostly between 25 and 35 CPM but 0.00 on the microsieverts/h and the mR/h.
Even with a handful of old thorium mantles, which got the thing clicking away quite merrily, there were only zeros from the dosage settings after an hour.
I think it's a dud but just wanted to check whether I'm missing anything?
Many thanks |
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| Reply #1
3z_phoenix
3 Posts |
Posted - 09/22/2025 : 03:01:11
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hi Shonky,
for me, this sounds like "lost" calibration-data, bcs.
some math is used to convert the CPM-value into microSivert per hour.
please have a look into "initional settings", if you can find something
like "Tube calibration" the value there must exist and no Zero-value.
sorry, i only have a GQ-GMC-500+ and i am not sure what Tube are used
at your device...
but sure our EmfDev will take-over so he read about your problem...
meanwhile i try to study the hardware details about your device...
kind regards, 3z_phoenix |
...the difference between democracy and anarchy are 3 canceled main meals ~ONLY~
[the first rule at my priv. survival-handbook] |
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Zero dose readings
