Abstract: A yarn utilizing machine, in particular a circular knitting machine, having a plurality of yarn utilizing stations is provided with a corresponding number of supply means for the yarn. At each supply station, there is a yarn tension or yarn supply quantity monitoring device that cooperates with the yarn. This monitoring device includes a transducer cooperating with the yarn as well as a measuring circuit that emits a signal corresponding to the monitored parameter. To enable recognition of only the deviation of one parameter, independent of the absolute value of the parameter, means are provided for generating a reference value, which is dependent on the measured signals of all the measuring circuits. Each yarn utilizing station or each yarn supply means is provided with a deviation signal circuit, which has two inputs; at least a portion of the reference value is fed into one of the inputs, while at least a portion of the measured signal is fed into the other input.