Abstract: The present invention relates to a system and method for continuous monitoring of system health in closed water systems. Sensors are provided to measure a plurality of system parameters. The measurements are compared to threshold ranges. A diagnosis of system health, specifically in relation to corrosion, is derived from the comparison of at least a first parameter to its threshold range. The diagnosis is further refined by comparison of a further parameter to its threshold range. Also disclosed are example sensors and methods, including galvanic sensors, optical corrosion sensors and methods for monitoring the effectiveness of inhibitors in the water system using conductivity measurements.

Abstract: A device for indicating the time integral of a monitored parameter comprising a strip of electrochromic material (2), e.g. tungsten trioxide, an electrode (3) at one end of the strip and an electrolyte (4) arranged so that, upon activation, electrons pass from the electrode (3) to the electrochromic material (2) causing the latter to change color so that a color change boundary (7) advances along the strip, the rate of advancement being determined by the supply of electrons between the electrode (3) and the color change boundary (7), which in turn is responsive to changes in the monitored parameter. The device may be used in the form of a self-powered cell needing no power source, as a time temperature indicator suitable for application to perishable commodities.