Elektročas HH3: the most accurate pendulum clock on the planet

The Elektročas HH3 is touted as the most accurate pendulum clock, capable of maintaining precision to within one second over 158 million years. This master clock, produced since the 1950s, was restored after suffering from water damage and neglect. The restoration was completed by a family horology service, allowing the clock to find a new home in an office. The HH3 utilizes an invar pendulum to minimize temperature effects, with an initial accuracy of 0.1 seconds per day. The project aims to synchronize the HH3 with a Caesium fountain clock at CERN, which serves as a primary frequency standard. The synchronization involves a Phase Locked Loop (PLL) that measures the pendulum's swing period and adjusts it using a novel Chain Controlled Oscillator (CCO) to maintain accuracy. The clock's stability has been tested, revealing a correlation between pendulum period and barometric pressure. Future improvements are planned to enhance the PLL's sophistication, ensuring the clock remains accurate over extended periods. The project has already shown promising results, including the clock's ability to detect seismic activity.

- The Elektročas HH3 is the most accurate pendulum clock, with a precision of one second over 158 million years.

- The clock was restored after significant damage and is now housed in an office.

- A Phase Locked Loop (PLL) is being developed to synchronize the HH3 with a Caesium fountain clock at CERN.

- The project has demonstrated the clock's stability and its ability to detect environmental changes.

- Future enhancements to the PLL are planned to improve long-term accuracy.