[ntp:questions] Re: HowTo calibrate system clock frequency using NTP
Daniel Kabs
daniel.kabs at gmx.de
Fri Feb 17 08:49:40 UTC 2006
Richard B. Gilbert wrote:
>> Hal Murray wrote:
>>> What sort of accuracy are you expecting?
>> I hoped to measure the time drift within (or better than) 1 PPM
> To what purpose? The drift will vary with the temperature and you are
> not planning to operate these devices at a controlled temperature. <...>
I'd like to calibrate the system clock, i.e. correct the frequency
offset (at a fixed temperature and with certain accuracy, say 5 PPM).
I also want to measure how the time drift varies with temperature.
To do this, I think, I'll have to find out to what uncertainty I can
measure the time drift of my system clock and how I can improve on this.
I know, I can always resort to running NTP on my system configured for a
reliable time server and then read the drift file. As this process takes
some time (at least one day for reasonable convergence) and I wanted to
compare with other methods of measurement I am also trying to determine
the time drift using offset readings.
Cheers
Daniel
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