PTB-NIST bilateral comparison of microwave noise power in coaxial transmission line

The Physikalisch-Technische Bundesanstalt and the National Institute of Standards and Technology have compared microwave noise power in coaxial transmission lines. Each laboratory measured two solid-state noise sources at 2.0 GHz, 4.0 GHz, and 8.0 GHz relative to their primary thermal noise standards. The agreement between laboratories is better than 0.07 dB, which is within the stated uncertainties of the two services, namely +or-0.06 dB for NIST, and +or-0.04 dB for PTB (confidence level: 0.95).<>