A schematic representation of the Vitrocell® VC 10. [A] Computer, software controller, which determines machine settings and smoking parameters. [B] Smoking Robot carousel where cigarettes are loaded and smoked. For GVP studies a Cambridge filter pad was installed into the line between the smoking carousel and the piston, for removal of the particulate smoke fraction. [C] Piston and syringe, which draws and delivers cigarette smoke to the dilution system. [D] Dilution of whole smoke occurs in the dilution bar. [E] Smoke exposure module which maintains cells at the ALI. To measure particulate dose, a quartz crystal microbalance was incorporated into the chamber, as shown, in position 4.