An open-ended coaxial probe separated from the investigated medium by a thin non-conducting layer (foil) is proposed for making dielectric permittivity measurements within the RF range. The method was originally applied by the authors for intraoperative tissue assessment. but it could also be suitable for food control (requirement of purity) or measurements in aggressive media (protec... https://www.globalspecialtyfoods.com/product-category/puffco-proxy-accessories/