Modern knowledge-intensive branches of industry require industrial intelligent sensors with enhanced metrological reliability. Such sensors are expected to provide many years of operation without maintenance. The specific scientific problems that emerge while developing such sensors are considered. These problems include: experimental evaluation of quality of sensor design and technology; development of on-line strategies for metrological self-checks of sensors as well as of methods to provide self-correction and fault-tolerance. Possible ways of solution of these problems are outlined.