In this paper, we propose a stand-alone, battery powered, wireless temperature sensor that can be used for diagnostic purposes in harsh industrial environments, including magnetic interferences and very low pressure (vacuum). Being easily mountable and removable during machine stoppage, this autonomous temperature sensor can be used at any location in a machine to gather temperature data over a period of a few months. The proposed sensor is realized with easily available, off-the-shelf components. It outperforms wireless temperature sensors available on the market in terms of the resolution achieved: 0.2 mK (3 sigma/ 1 reading per second), and the power consumption: <1 mW.@en