Diameter measurements of precision coaxial air lines at NMC for scattering parameter measurement traceability

In coaxial impedance measurements, air lines are one of the realizable and calculable impedance standards directly traceable to the national standard of length. NMC has recently established an automated measurement system for air-gauging diameters of the lines with KRISS design and fabrication. Diameters air-gauged at NMC and KRISS are compared to demonstrate the measurement capabilities and to validate the equivalence of two automated air-gauging systems with three 50 Ω type-N beadless air lines.