over what durration will the clocks accuracy be measured? (seconds, minutes, hours, days, months, (years)?
"accuracy to be measured before disciplining with GPS, WWVB....." "calibration should be within the grasp of a layman" Could some clarification be given here? I'm thinking that the clock could be self calibrating say automatically or by user button press but this presents a chicken and egg problem in light of the quotes above. Many of the designs I've seen previously keep an internal memory that tracks and allows compensation for parameters such as drift, aging rate, and temp coefficient updating these variables when connected to a known better reference. in this way the accuracy improves with time. while a layman could calibrate this type of clock quite easily (or would not need to as the clock would calibrate itself) any calibration pretty much by definition is a comparison to a better reference (wwvb, gps, hydrogen maser, rubidium, cesium beam, etc.) so how do you expect calibration to be accomplished without, use of a better standard? would such a device be allowed to remember and store calibration factors during its initial calibration or would this fall into the category of discipline? I would say that the initial determination and programming of calibration factors (which will vary among devices) is calibration, after which it becomes discipline as the routine continues to run. What's your interpretation? Eric On Nov 30, 2007 6:43 AM, <[EMAIL PROTECTED] > wrote: > A number of people have asked for more details on IEEE Spectrum's digital > clock competition, so we've formulated the following list. Throughout, the > idea is to build a clock that an ordinary person would want to use, in an > ordinary home. That's why we want a display that can be read with ease > from across a room. > > > Operating environment and other specs for IEEE Spectrum's Digital > Clock Competition: > > --between 10 and 50 degrees C > > --between 0 and 100 percent relative humidity > --with seven-segment LED display, no smaller than 0.56 inches > --no limit on power > --calibration should be within the grasp of a layman > --lacking an oscilloscope here in the office, we will check > accuracy against a WWVB or GPS signal (other suggestions--even volunteers > to help in the judging--are welcome) > --parts to be available from any of the big distributors > (RadioShack, Mouser, DigiKey, Maplin, etc.) or, in sufficient quantities > (100s, say) from a surplus store > > > > > Philip E. Ross > Senior editor > IEEE Spectrum Magazine > 212 419 7562 > http://www.spectrum.ieee.org > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.