The invention relates to a test cassette for measuring the torque of a winding mandrel of an apparatus for recording and/or playing back signals on and/or from a magnetic tape wound on reel hubs in a cassette (hereinafter referred to as a tape cassette apparatus), the apparatus comprising winding mandrels with which the reel hubs engage to receive torque therefrom.
German Offenlegungsschrift No. 29 32 526 discloses a test cassette in which there is arranged a spring balance which measures the dragging force of a tape which is wound around the reel hub driven by the winding mandrel. A problem associated with this known test cassette is that when it is used in a closed apparatus, for example a car-radio/cassette recorder, the measurement values indicated by the spring balance cannot be read directly from the spring balance. For reading the measurement values DE-OS No. 29 32 526 describes a special measuring indicator which is coupled to a narrow side of the cassette via a mechanical cable system. A disadvantage of this arrangement is that the cassette insertion slot must be visible to the person carrying out the test.