NIST-F1

NIST-F1 is an atomic clock facility at the National Institute of Standards and Technology in Boulder that measures time by observing cesium atoms in a vacuum chamber. This facility was specifically engineered to provide the most accurate time measurements needed for GPS navigation, telecommunications, and power grid operations.

The facility began operations in December 1999 as the primary time and frequency standard for United States civilian measurements. It replaced earlier atomic clocks and marked a significant advancement in improving the accuracy of time measurement nationwide.

This atomic clock facility represents a cornerstone of modern scientific advancement in precision timekeeping technology for the United States measurement system.

Visitors can only view the facility from limited public areas, as it operates in a controlled laboratory environment not open for general access. Contact NIST directly if interested in tours or educational demonstrations about timekeeping technology.

The accuracy is so remarkable that it would take approximately 20 million years to lose or gain even one second. This demonstrates how precisely atomic movements can actually be measured.

GPS coordinates: 39.99400,-105.26400

Latest update: December 7, 2025 10:05