[ntp:questions] Re: HowTo calibrate system clock frequency using NTP
daniel.kabs at gmx.de
Mon Feb 6 12:36:01 UTC 2006
Hal Murray wrote:
> What sort of accuracy are you expecting?
I hoped to measure the time drift within (or better than) 1 PPM
> The main contribution to changes in drift is temperature.
Right, I cooled the system down by about 30° and the clock drift
increased by about half a second per day (measured with Plan B).
> Does your environment have a stable temperature?
As stable as "room temperature" gets :-)
> Are you calibrating your systems in the same location that
> you will be running them in? (Or calibrating them on a test
> bench and shipping them to a customer?)
The latter. While the system on the test bench, I wanted to measure the
time drift in order to calibrate the system clock. I also have a
temperature controlled cabinet available so I may try this again in a
more stable environment, if neeeded. But upto now, I am faced with two
different methodes for gathering the frequency offset: both give a
precise reading if repeated, but as the results differ, only one can be
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