The inductive response of single crystals of UPt3 have been studied from 1 K to 70 mK using mutual inductance techniques to measure and at 31.7 and 317 Hz and tunnel-diode resonant methods at 3 and 16 MHz, for the excitation fields parallel to the symmetry axis of the crystal. A double bump in the measurements is clearly distinguishable and is consistent with the H=0 phase diagrams of other workers. The temperature dependence of the magnetic penetration depth has been extracted from the measurements, which indicate that the low-frequency results are linear for T/Tc<0.5, while the high-frequency data indicate a power-law dependence close to T2. © 1992 The American Physical Society.