NIST plays a crucial role in developing and maintaining measurement standards that underpin the U.S. measurement system. These standards include:
1. Time and frequency standards: NIST’s F1 and F3 atomic clocks serve as the basis for civilian timekeeping in the U.S. GPS-enabled devices use these standards for precise time and frequency measurements.
2. Mass standards: The Kibble balance, a device that measures mass by comparing it to electrical energy, serves as the basis for all mass measurements. NIST helps ensure traceability and accuracy in mass measurements through a chain of calibrated standards.
3. Electrical standards: The Josephson junction, a device that generates precise electrical voltages, serves as the standard for the electrical volt.
4. Length standards: The meter is defined as the distance light travels in 1/299,792,458 of a second in a vacuum. NIST helps ensure accurate length measurements through a chain of calibrated standards.
These measurement standards are essential for various applications, including aerospace, radiation dosimetry, and optical mirror calibration. NIST works with organizations like Sandia National Laboratories to ensure accurate and traceable measurements across the U.S.
Source: https://www.nist.gov/feature-stories/why-you-need-standards/measurement-standards
Keywords: measurement standards, atomic clocks, Kibble balance
