Improvements in test technology for next generation microsystems is now becoming essential, especially in sensing applications as in most cases, each sensor has a unique set of characteristics causing inevitable difficulties associated with calibration and validation. Ideally, a microsystem should generate a calibrated output and a reliability indicator. IEEE1451.2 has been developed to provide a standard interface yet research into methods of providing these features through Built-In Self-Test (BIST) and On-line monitoring (OLM) techniques is still needed. One of the current industrial techniques uses multiple sensors to determine faults allowing systems to be temporarily reconfigured until the problems are resolved. This technique is only economical if multiple sensors with a strong functional correlation are present within the original system. In case only one sensor is present, using redundancies within this sensor would be more economical than adding extra sensors for test purposes. The aim of this paper is to review generic properties of sensor systems to identify areas where mixed signal testing techniques could be adapted for sensor test and to identify areas for further research.