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A technical guide to Clock B raw data
12-Nov-2016
This page will be valid some time after the publication of the book about Clock B by Oxford University Press.
28-May-2020
The book has been published!
Harrison Decoded: Towards a Perfect Pendulum Clock
My observations and plots of Clock B are found in chapter 8.
The following is the data used to create the plots:
Details of Excel columns:
- mjd-stamp — timestamp of data, MJD (Modified Julian Date)
- utc-date-time — timestamp of data, in traditional calendar format, UTC
- time-error — time error of clock as measured by Microset/GPS, units: seconds
- rate-hourly — computed clock rate, hourly, in df/f units
- rate-spd — computed clock rate, hourly, in traditional seconds-per-day units
- baro-mbar — environmental sensor, barometric pressure, units: mbar
- temp-c — environmental sensor, temperature, units: degrees C
- rh-pct — environmental sensor, relativity humidity, units: percent
- gate-time — photogate blink time, a proxy for velocity, amplitude, units: seconds
- energy-pct — photogate blink time, translated to kinetic energy, units: percent from mean
More details in the book chapter. In summary,
- The early 110 day run in 2012-2013 shows promising results but a strong barometric effect.
- The later 130 day run in 2014-2015 shows that the barometric adjustment was successful,
although now a slight temperature effect can be seen.
This data begins 1-Dec-2014 and contains the official 100-day trial, which began 1-Jan-2015.
- The 476 day run in 2014-2015 is the longest continuous data available at this time.
This data begins 23-Jul-2014 and ends 12-Nov-2015.
It is a superset of the 130 day run above.
Clock B was moved from the workshop to the main gallery
and that concluded this series of data collection.
Composite plot of 1st run (2012-2013) and 2nd run (2014-2015).
For easy comparison each plot has identical scale.
Click for full resolution (2400x1600): clockb-v6-fig8.3-fig8.5.png
Contact me for questions about the data, plots, analysis, or measurement anomalies.
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