Abstract: A method of detecting and locating a fluid leakage in a fluid pipeline network includes providing a plurality of sensors in an area of the pipeline network. Each sensor is configured to output data relating to an acoustic or vibration measurement associated with a part of the pipeline network proximate said sensor. The method further including recording the acoustic or vibration measurement output data, transforming the output data from a time domain to a frequency domain, determining a leakage condition, computing a sum value of the measured frequency values and associating said sum value with a corresponding sensor of the plurality of sensors, and locating a source of the fluid leakage by identifying one or more sensor(s) of the plurality of sensors in the area of the pipeline network that is closest to the source of the fluid leakage.

Abstract: The invention provides a method of compensating for the error of a signal indicative of the mass of air flow output from an air mass flow sensor for an internal combustion engine, the method comprising deriving an air mass flow value from an air mass flow sensor output, calculating a compensated air mass flow value based on the air mass flow value and a compensation value, calculating an estimated air mass flow value from engine operating parameter values, calculating a new compensation value based upon the compensated air mass flow value and the estimated air mass flow value and using the new compensation value for subsequent calculations of the compensated air mass flow value.

Abstract: The invention provides a method of compensating for the error of a signal indicative of the mass of air flow output from an air mass flow sensor for an internal combustion engine, the method comprising deriving an air mass flow value from an air mass flow sensor output, calculating a compensated air mass flow value based on the air mass flow value and a compensation value, calculating an estimated air mass flow value from engine operating parameter values, calculating a new compensation value based upon the compensated air mass flow value and the estimated air mass flow value and using the new compensation value for subsequent calculations of the compensated air mass flow value.