TOWARDS AN ELECTROMAGNETIC PRESSURE STANDARD: DIELECTRIC PERMITTIVITY OF HELIUM AND ARGON MEASURED WITH QUASI-SPHERICAL MICROWAVE RESONATORS AND CROSS CAPACITORS

摘要

To develop electrically based pressure standards, we measured the dielectric permittivity of helium (epsilon)_(He)(p,T) and argon (epsilon)_(Ar)(p,T) using two independent techniques (quasi-spherical microwave cavities and cross capacitors). At 7 MPa, the microwave results for helium differ from NIST's pressure standards by (18+-37)X10~(-6).