Wednesday 28-APR-1999 we changed the ERP S/H card for channels 4T01,
4T02,4T03 and 4T04 due to a strange behaviour of ADC-A for 4T01-1.
More precisely, since about run 16900, the Laser ERP calibrations revealed
that ADC-1A (the side-1 "anode", i.e. non-attenuated PMT signal ADC) would
only reach a value of ~3000 (instead of the standard overflow value of
4095) and it would then decrease with increasing light.
We swapped in a (spare) ERP S/H card that was recently brought to G.S.
by Hwi Kim. Please note that, just as it happened a week ago when we
changed the ERP S/H for 4E08-11, the first spare card we tried to swap in
did not work - 4 out of the 8 inputs resulted dead.
We have run all ERP calibrations today and the data so far look good.
Yet, keep an eye on the data quality for this channel. The first run
following the swap is 17523.
Regards,
Ioannis Katsavounidis