operational tips of the saw toothed clothing 52 of the licker in 50 and the working or operational tips of the spiked clothing 16 of the main carding cylinder 10 for which purpose the same sensors 24 and 26 are used in the same manner as in the case of the measurement of the spacing of the stationary flat 14 depicted in fig1 the sectional plane of fig2 contains both the axis of rotation 12 of the main carding cylinder 10 and the axis of rotation 54 of the licker in 50 so that the spacing n in this sectional plane is the smallest possible spacing in this exemplary embodiment depicted in fig2 counter elements 56 and 58 are structured to be annular or ring shaped and are co axially arranged with respect to the axis of rotation 54 of the licker in 50 whereby the spacing n can be measured at different angles of rotation of the licker in 50 in order to obtain information concerning the deformation or eccentricity of the latter when the licker in 50 is not in rotation information can likewise be obtained with respect to possible deformation or eccentricity of the main carding cylinder 10 whereby such information can also be determined by means of any other carding machine part which cooperates or interacts with.