Knowledge of the mass flow-rate of cotton and its by-products produced during ginning should improve process control. Tests of a previously developed device were conducted to evaluate its capabilities in measuring mass-flow of lint-cleaner-waste (LCW) in the lint-cleaner-exhaust of both a small research gin and a full-size, commercial gin. Results of regression analysis of data collected in the research gin revealed a good correlation (R² = 0.88) between sensor output and actual mass flow-rate of LCW through the device. The sensor was then reconfigured and installed and tested in a commercial gin. Linear regression analysis revealed a high correlation (R² = 0.95) between sensor output and the amount of LCW that passed through the device during tests in the commercial gin.