Hi Karl I look at the 16 bit digitizer as an alternate to a autogain system. I tried autogain changing during events and the bookkeeping became a problem as did the slight zero shifts during gain changes. I would like to record both local and distant signals and seem to use most of the 16 bits . The smallest event p-p I recorded recently is about 500. With a use of 10% of this for minimum signal it would be around 50. I have been wanting to lower my gain a little recently. Looks like with todays event down south I may clip again. Regards Barry Karl Cunningham wrote: > Hi Sean-Thomas -- > > You're right. I didn't mean accuracy. But I'm not sure I really meant > resolution either. Perhaps "precision" (or distortion level) might have > been a better choice of words. > > What I was trying to say (and please correct me if I'm wrong) is that it > isn't necessary for the system to faithfully record the waveform to within > 15ppm (16 bits) for a full-scale signal. For very small signals you want > to get as many bits of good data as possible. But if the signal is large, > perhaps allowing an imprecision (in other words distortion, including > aliases) of something like 8 bits (0.4% of the peak-to-peak signal at the > time) may be good enough. Of course, it depends completely on what the > data is to be used for. > > I was suggesting that the compromise of allowing unintentionally aliased > out-of-band signals may be ok as long as they are below some fraction of > the overall signal level at that time, given the resultant benefit of > decreased circuit complexity. > > Karl > __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>