A toner which combines excellent cleaning ability, image quality and durability, as well as a developer and an image forming method using the toner are provided. In a case where facsimile communication via the Internet based on the ITU-T Recommendation T. The dispenser includes a pressure sensor for measuring the pressure of the diluent at the inlet. In a preferred embodiment, the dispenser houses miniature zinc air batteries, secured to the base using an adhesive platform. The model parameters might also take account of manufactured asymmetries. The screw is configured to generate andor maintain axial compression between threads formed in leading and trailing sections of the screw either by virtue of pitch differential in the threads or the way in which the screw is installed.