Load/Short/Open Calibration Standard DC 8GHz, N (m), R&S ID 1300.7810.03. The R&S FSH-Z28 calibration standard is specially designed for field use. It combines all calibration standards (open, short, 50 ohm load) necessary for scalar or vector network analysis as well as DTF measurement. Hung around the user's neck, it is always handy when needed for a calibration.