A head unit for use in a droplet ejection apparatus is provided with a plurality of droplet ejection heads for ejecting liquid material of a predetermined color onto a base as droplets. The system and method includes the use of an integration scenario. Furthermore, a robustness of the proposed FQ channel estimation scheme to accommodate errors in a channel delay profile and to errors in a channel power profile is demonstrated through simulations. The multi-function antennas are configured for being mounted to an exterior surface of a pressure vessel. The seal element includes a first bushing, a second bushing, and a dry seal assembly including a wiper that defines a diameter that is smaller than the shaft diameter. The electronic component has a proximal end conductively coupled to a lead conductor and a distal end conductively coupled to a lead electrode.