tailieunhanh - Advanced Microwave Circuits and Systems Part 12

Tham khảo tài liệu 'advanced microwave circuits and systems part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Broadband Complex Permittivity Determination for Biomedical Applications 379 This uncertainty evaluation is also the verification of self-consistency of the developed relation between the measured reflection coefficient and the calculated complex permittivity Eq. 17 . Uncertainty evaluation is based on the relevant information available from previous measurement data and experience and knowledge of the behavior and property of the distilled water and the measurement instruments used referred to as Type B uncertainty evaluation . Sources of uncertainties and related standard and combined standard uncertainties Tab. 2 and 3 are evaluated with the aid of guidelines NIST 1999 . source of uncertainty f MHz standard uncertainty 30 repeated observations 434 915 30 random effects 434 915 30 systematic effects 434 915 30 combined standard uncertainty 434 915 Table 2. The uncertainty budget N-type probe sources of measurement uncertainty are evaluated at important frequencies from a medical point of view source of uncertainty f MHz standard uncertainty repeated observations 434 915 1800 2450 random effects 434 915 1800 2450 systematic effects 434 915 1800 2450 combined standard uncertainty 434 915 1800 2450 Table 3. The uncertainty budget SMA-type probe sources of measurement uncertainty are evaluated at important frequencies from a medical point of view 380 Advanced Microwave Circuits and Systems The applied recommendations given in NIST 1999 and mentioned also above are following Repeatability The measurement procedure was performed twenty times over a short period of time minutes in a single location with the one-off application of measuring instruments in order to observe the same results. Random Effects The measurement procedure was performed ten times over a long period of time days and months at a single location with the .