Three orders of magnitude would be hard to see on a standard meter. A 3 =BD digit DVM would be capable of that display, but you=92re back to the original problem of it=92s not very visual. What might be satisfactory i= s to take an A/D chip with 10 bits of resolution or so =96 you=92ll only ne= ed 8 bits of that, but in order to guarantee no missing codes and so forth I=92m suggesting a 10 bit one. The cost is still only a few dollars for the low frequency sampling you=92ll be using. I=92d then feed the decod= ed A/D output to a string of LED=92s, 255 in this case. If you get ambitiou= s you could go for 9 bits and 511 LED=92s. Now a magnitude 1 could be 2 LED=92s on, magnitude 2 would be 20 LED=92s on, and magnitude 3 would be = 200 LED=92s on. That would be very visual and could be constructed to fit th= e area you have. As I sit here, I=92m thinking of that scene in =93Forbidd= en Planet=94 where they=92re in the power control room and the meters are go= ing up one by one as the =93ID=94 monster draws on the power to break down th= e vault-like doors =96 but you probably don=92t want to get quite that carr= ied away! Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>