Introduction

The pendulum clock in Trinity College, Cambridge was installed in 1910. It is remarkably accurate, known to be better than one second per month, but it was only in 2009 that a system was finally introduced 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):

The clock seems to be running quite stably at the moment, and the webcam is running again.

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.

Comments (see all | edit)

07 Feb 2012 [15:09]
A whole heap of helpers today ... Harry Clift, Eloise Hunt, Lynn Clift, Janet Procter - all very muscley!
31 Jan 2012 [13:17]
Jonas Coene helped with winding - thanks!
24 Jan 2012 [13:13]
Many thanks to Simon Raikes for throwing his weight around today!
17 Jan 2012 [12:06]
Winding helpers today: Madelaine Crush, Janice Chambers and Rob Hogan - many thanks!
10 Jan 2012 [19:00]
Not sure what caused this gap in data. The PC seems to be fine because weather data has been collected. Perhaps the GPS receiver was doing a software upgrade?
10 Jan 2012 [16:58]
Thanks Janar Davletov (from the Bursary) for help with winding!