Measuring the limpness of a note is necessary to separate a worn note out of circulation. Several methods are disclosed which can be used either alone or in combination to test for limpness. One method measures the note's ability to reflect light or transmit the light. Another method measures the response of the note to an acoustic wave. Another method measures the note's deflection to a pressure or force. Yet another method measures the dielectric value of the note when placed between the plates of a capacitor. A final method involves measuring the thermal conductivity of the note. In each case, a limp note will produce distinguishable results from a stiff note.