Method for detecting, locating and quantifying obstructions in a gas network under pressure or vacuum; the gas network comprising: - one or more sources of compressed gas or vacuum; - one or more consumers or consumer areas of compressed gas or vacuum applications; - pipelines or a network of pipelines to transport the compressed gas or vacuum from the sources to the consumers, consumer areas or applications; - a plurality of sensors (9a, 9b, 9d) providing one or more physical parameters of the gas at different times and locations within the gas network; characterized in that the gas network is further provided with a number of controllable or adjustable throttle valves situated in the aforementioned pipelines and with one or more state sensors capable of recording the state or status of one or more throttle valves and that the method comprises the following steps: - a training phase in which a mathematical model is drawn up between the measurements of a first group of sensors(9a, 9b, 9c, 9d) comprising a plurality of pressure sensors, possibly a number of flow sensors and possibly a number of state sensors at different locations in the gas network and a second group of sensors (9a, 9b, 9c, 9d) on the basis of different measurements of these sensors (9a, 9b, 9c, 9d), the second group of sensors comprising a plurality of state sensors at different locations in the gas network, wherein a sensor from the first group is not in the second group and vice versa, wherein one or a plurality of adjustable throttle valves are controlled in a predetermined order and according to well-designed scenarios to generate obstructions; - an operational phase in which the mathematical model established between the measurements of the first group of sensors (9a, 9b, 9c, 9d) and the second group of sensors (9a, 9b, 9c, 9d) is used to detect, locate and quantify obstructions in the gas network; wherein the operational phase comprises the following steps: - reading out the first group of sensors (9a, 9b, 9c, 9d); - from the readout measurements of the sensors (9a, 9b, 9c), calculating or determining the value of the second group of sensors (9a, 9b, 9c, 9d) using the mathematical model; - comparing the calculated or determined values of the second group of sensors (9a, 9b, 9c, 9d) with the read values of the second group of sensors (9a, 9b, 9c, 9d) and determining the difference between them; - determining whether an obstruction is present in the gas network on the basis of the aforementioned difference and any of its derivatives comprising a mathematical quantity extractable from the difference; - generating an alarm if an obstruction is detected and/or determining the location of the obstruction and the degree of obstruction and/or generating the associated obstruction cost, wherein the location is determined by controlling the adjustable throttle valves 10 in a predetermined order. - one or more sources of compressed gas or vacuum; - one or more consumers or consumer areas of compressed gas or vacuum applications; - pipelines or a network of pipelines to transport the compressed gas or vacuum from the sources to the consumers, consumer areas or applications; - a plurality of sensors (9a, 9b, 9d) providing one or more physical parameters of the gas at different times and locations within the gas network; - a training phase in which a mathematical model is drawn up between the measurements of a first group of sensors(9a, 9b, 9c, 9d) comprising a plurality of pressure sensors, possibly a number of flow sensors and possibly a number of state sensors at different locations in the gas network and a second group of sensors (9a, 9b, 9c, 9d) on the basis of different measurements of these sensors (9a, 9b, 9c, 9d), the second group of sensors comprising a plurality of state sensors at different locations in the gas network, wherein a sensor from the first group is not in the second group and vice versa, wherein one or a plurality of adjustable throttle valves are controlled in a predetermined order and according to well-designed scenarios to generate obstructions; - an operational phase in which the mathematical model established between the measurements of the first group of sensors (9a, 9b, 9c, 9d) and the second group of sensors (9a, 9b, 9c, 9d) is used to detect, locate and quantify obstructions in the gas network; - reading out the first group of sensors (9a, 9b, 9c, 9d); - from the readout measurements of the sensors (9a, 9b, 9c), calculating or determining the value of the second group of sensors (9a, 9b, 9c, 9d) using the mathematical model; - comparing the calculated or determined values of the second group of sensors (9a, 9b, 9c, 9d) with the read values of the second group of sensors (9a, 9b, 9c, 9d) and determining the difference between them; - determining whether an obstruction is present in the gas network on the basis of the aforementioned difference and any of its derivatives comprising a mathematical quantity extractable from the difference; - generating an alarm if an obstruction is detected and/or determining the location of the obstruction and the degree of obstruction and/or generating the associated obstruction cost, wherein the location is determined by controlling the adjustable throttle valves 10 in a predetermined order.