A pulsed NMR system for platinum nuclear spin thermometry and for measurements of the nuclear spin‐lattice relaxation time &tgr;1has been developed. The nuclear free precession signal is detected with a fast linear detector and anRCintegrator. The &tgr;1measurements were performed by the transient recovery method with the aid of automated circuitry multiplexing of the linear detector output into four separate integrators. The thermometer was tested between 10 mK and 2 K using a powdered platinum sample. Within the experimental accuracy of about 2% the amplitude of the nuclear free precession signal was found to be proportional to 1/T. The thermometer could be calibrated with the aid of the Korringa relation &tgr;1T=&kgr;, with &kgr;=29.6 msec K. Thermal equilibrium problems of the &tgr;1measurements are discussed in detail.