A solution of 0.17 M of Acetaminophen in 50 mL acetonitrile (MeCN) was heated to begin distillation (Figure ). A charge of toluene via the dosing pump was added when HeinSight2.0 detected that the threshold volume was reached. Unlike the previous example, the rate of distillation did not appear to change as significantly during the first few solvent recharges. Throughout, HeinSight2.0 effectively monitored the reactor volume even though solid and residue began to form and obstruct the viewing window. A dramatic change in the rate of distillation occurred at the fifth dose of toluene, leading to rapid crystallization of acetaminophen. Assuming the distillate likely contained mostly MeCN, this point also corresponded to when the solvents had mostly exchanged and the solution became toluene-rich, thus driving crystallization due to the reduced solubility of acetaminophen in toluene. HeinSight2.0 correctly detected the onset of crystallization at the fifth dose through the appearance of "solid" class, as shown in image 4 of Figure . For clarity the solid trend was not shown in the figure and replaced with a pink shade. The increase in temperature rate at the fifth dose further supported the point of nearly complete solvent exchange.