The present disclosure relates generally to a faucet valve cartridge configured for use within a dual handle faucet. A system for enhanced tamper and malware resistance can include a harvardizer configured to receive comingled instructions and data and produce separated instructions and data. The navigation apparatus further comprises a unit for searching a further route from a further current position to the destination in response to a predetermined command. A method of analyzing a component such as urea in a biological fluid is also provided.