I think Tom Knox is right on the money. I am quite interested in logging environmental history, particularly during transit. I participated in the EEVblog USA Cal club Round 2 and have proposed adding an MSP430 data logger to the kit for Round 3.
I'm adding support for a real time clock, temperature and humidity to the AR488 GPIB-USB package using an Arduino Mega 256. AR488 is an extension of the Prologix commands, so it is easy to implement logging in any scripting program. I also plan to add relay control of HP 44421A boards as well as SMA relays for RF work. At the moment I'm focused on developing an Arduino Uno shield which can be profitably sold on ebay for $15 + $5 for each GPIB device in excess of 1 and handle 10-12 devices. All in a nice plastic enclosure using ribbon cable and IDC Centronics connectors. I've built one hand wired unit, but it did not use a 2x12 0.1" header. So making it up was rather time consuming and error prone. I spent several years working in the area of mechanics of materials and I think that it is possible to characterize the time and environment dependent behavior of voltage references accurately enough to significantly reduce the uncertainty. I asked previously for time series of voltage references logged from initial start up, but never got any data. If you have such data you're willing to share, please send it to me. The graphs I've seen look to be of the form A +/- B*exp(f(t)). This is a classic relaxation process. I'm fairly experienced at modeling that. My numerical experiments have found that predictions based on historical measurements can be made to a few per cent error for a period equal to the length of the history. But I don't yet have real data to test the techniques with. So, please, if you have data, send me it to me as ASCII text such as CSV format. Have Fun! Reg _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/volt-nuts_lists.febo.com and follow the instructions there.
