Procedure

1.

Wire the system as shown in the ESR Manual. The Helmholz coils can be connected to the power supply either in series or in parallel. Series wiring provides extra protection against accidental overload, but may not allow sufficient current for good results. Try wiring the coils in series first, and switch to parallel if this does not work.

2.

Measure the Lamor frequency for as many values of the magnetic field as you can. Use the results at each frequency to calculate a value for the gyromagnetic ratio. Remember when you do this that the Lamor frequency is given in in Eq. 6, whereas the ESR display shows the oscillation frequency in Hz. Calculate the mean and standard error for your results.

3.

Compute an error term for the gyromagnetic ratio using propagation of error techniques. Assume that the random error in each of your measurements is due to the instrument's resolution. Compare this term to the actual error you found in the previous step.

1999-09-14