The present invention provides a transmitter conforming to the EER method in a wide frequency band at high efficiency. A display device includes a plurality of pixels and a drive circuit which drives the plurality of pixels. The system also includes a transient air flow estimation for further improving setpoint speed accuracy. The transmission is driven by a motor and provided, on its side which is external during use, with an excavation apparatus. The hinged elements are secured by an over-center latching latch such that when the container is fully closed the rib exerts a small and substantially uniform force against the gasket to form a seal against fire and water.