The pendulum clock in Trinity College, Cambridge was installed in 1910. It is remarkably accurate, known to be better than one second per month. In 2009 a system was installed to monitor the "going". The work was done as part of a 4th year MEng project at the Engineering Department. A sensor on the pendulum detects the going of the clock, which is compared to the accurate time signal from a GPS receiver.
Here is a graph for the last 30 days of drift (updated every 3 hours):
For an entirely mechanical clock the accuracy is remarkable.
A barometric compensator was installed at clock change - midnight 28 March 2010.
The clock is regulated as infrequently as possible so as to stay within +/- 5 seconds of the correct time. This enables the steady-state physics of the clock to be examined without unnecessary interference.
The black dots ● indicate that there is a comment relating to the time indicated. Blue arrows pointing down ▼ indicate that an adjustment was made to the Going of the clock by removing weights from the pendulum. Red arrows up ▲ indicate addition of weights to speed the clock up.
- 27 Aug 2014 [19:00]
- top-up wind with Martin Kyte (MRC LMB) - he wants to build a tower clock with a double 3 legged escapement!
- 24 Aug 2014 [18:45]
- winding and computer restart, trying to get weatherlogger to work!
- 20 Aug 2014 [16:00]
- computer restart, and top-up wind by Hilary Costello
- 17 Aug 2014 [20:00]
- winding by team Canada: Stephan Bots, Rick Enns, Hilary Costello
- 14 Aug 2014 [14:01]
- winding by Mark Rainer and (mostly) Daniel Flack - his first time!
- 10 Aug 2014 [14:50]
- reset drift correction by restarting clocklogger after changing the value of last_drift from 4.1 to 1.1
- 07 Aug 2014 [14:20]
- thanks to Mark Rainer for winding