Abstract: An electric machine includes a rotor rotatable about a rotational axis, by which an axial direction is defined, and a stator with stator windings, a coolant distributor space and a coolant collector space. The coolant distributor space communicates fluidically with the coolant collector space to cool the stator windings with a cooling duct. The stator includes stator teeth supporting the stator windings and protruding radially inward from a stator body of the stator. A stator groove is formed between two stator teeth which has a radially outer groove zone extending radially inward away from the stator body into a radially inner groove zone, the radially inner zone width of which is smaller than the radially outer zone width, when measured along the circumferential direction, of the radially outer groove zone. At least one stator winding is embedded, for thermal coupling, into an electrically insulating plastic arranged in the stator groove.

Abstract: A probe for measuring the hardness of concrete includes a body adapted to receive a retainer such that the combined body and retainer can be held in an aperture extending through a wall of a mould for the hardenable material, with the body extending from the inside of the wall. A sensor circuit includes detector elements supported by the body and disposed when in use in the concrete, and circuit terminals which face the exterior of the mould wall when in use, and are accessible through the retainer for connection to terminals of an external instrument. Preferably, the detector elements are conductive portions of a printed circuit board forming a resonator. The instrument can operate a switch in the probe which interconnects the terminals to indicate a good connection and measures resonator impedance at multiple frequencies.

Abstract: A probe for measuring the hardness of concrete includes a body adapted to receive a retainer such that the combined body and retainer can be held in an aperture extending through a wall of a mould for the hardenable material, with the body extending from the inside of the wall. A sensor circuit includes detector elements supported by the body and disposed when in use in the concrete, and circuit terminals which face the exterior of the mould wall when in use, and are accessible through the retainer for connection to terminals of an external instrument. Preferably, the detector elements are conductive portions of a printed circuit board forming a resonator. The instrument can operate a switch in the probe which interconnects the terminals to indicate a good connection and measures resonator impedance at multiple frequencies.