A further complication is that the measurement of γ′p involves the measurement of an electric current: this is invariably measured in conventional amperes rather than in SI amperes, so a conversion factor is required. The symbol Γ′p-90 is used for the measured gyromagnetic ratio using conventional electrical units. In addition, there are two methods of measuring the value, a "low-field" method and a "high-field" method, and the conversion factors are different in the two cases. Only the high-field value Γ′p-90(hi) is of interest in determining the Planck constant. COUNT 4
QSN1 How many methods of measuring the gyromagnetic ratio are there? ANS1 there are two methods of measuring the value QSN2 How do conversion factors compare in "low-field" and "high-field" methods of measuring the gyromagnetic ratio? ANS2 the conversion factors are different in the two cases QSN3 Which method is of interest in determining the Planck constant? ANS3 Only the high-field value Γ′p-90(hi) is of interest in determining the Planck constant QSN4 Why is the measurement of electric current an issue in the estimate of the gyromagnetic ratio? ANS4 electric current: this is invariably measured in conventional amperes rather than in SI amperes