Abstract: A position measuring device intended for a rotary electric machine. The position measuring device includes a position sensor and a fixing arm projecting with respect to the sensor compartment, wherein the fixing arm has an orifice exhibiting a central axis. The fixing arm has at least one slot made in the periphery of the orifice, the slot exhibiting a depth, in the direction of the central axis as far as a bottom wall, greater than or equal to 2 mm, the slot being configured to receive a tooth of a calibration tool. The invention also relates to the calibration tool cooperating with the position measuring device.