A plurality of training signal sets are transmitted. The devices may be formed from shape memory metals such as nitinol. A computer may determine a continuous smooth geographical location function fitted to the sampled geographical location data. Engagement with the inlet on the printhead during installation of the ink cartridge, compresses the annular skirt to open the outlet valve such that ink flows from the ink storage volume around the radially extending flange portion to the printhead. This may be implemented, for example, by welded-in split line elements which are also suitable for retrofitting.