PRECISE DIELECTRIC PROFILING OF ICE CORES - A NEW DEVICE WITH IMPROVED GUARDING AND ITS THEORY

Dielectric profiling (DEP), a capacitive method for measuring an ice c ore's electrical conductivity and permittivity, has been in use for se veral years. We have built an improved DEP instrument with a modified guarded-electrode geometry whose capacitance can be determined from po tential theory The new instrument can measure an ice core's conductivi ty and permittivity to within a few per cent error, a high enough accu racy to infer its density using well-known models.