Update 2011-05-26 22:19 CEST: Tonight around 21h, the readings from the FH40T suddenly ceased. No more clicks were detected. After some initial testing, no immediate cause for this malfunction could be found, the FH40T detection electronics seemed dead but the G.M. tube was still OK.
After an interruption of about an hour, I was able to continue the measurements with a spare (D.I.Y) counter circuit that I had already built, using the same G.M. tube FHZ76V.
|SI8B CPM measurement|