High-resolution measurements of the Larmor frequency in normal-liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$

Measurements have been made of the Larmor frequency of the normal ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ Fermi liquid with resolution better than 1/${10}^7$. The Larmor frequency was observed to increase on increasing temperature from the superfluid transition to above 40 mK in a constant 0.12 T external magnetic field. The shift has a temperature dependence that is negative and approximately proportional to the inverse temperature. The magnitude is of order 1/${10}^6$ and depends on pressure in the investigated range 0.3 to 21.7 bars decreasing substantially at the highest pressures.