Stock freeness is a critical variable in most papermaking applications. Several efforts have been made to measure freeness on a continuous or semi-continuous basis but most require high levels of maintenance and calibration effort to maintain reliability and accuracy. The Fibre Monitor Freeness Tester, by measuring drainage rates rather than volumes, moves continuous freeness measurement significantly down the road to minimization of these system shortcomings. Designed by a former mill superintendent, this instrument, once calibrated, provides accurate stock freeness measurements on a continuous basis with a minimum of maintenance headaches.