Abstract: An analyzer analyzing a fluid containing at least one substance to be analyzed and at least one inflammable substance containing a source of gas to provide a flux of diluent gas, an injecting nozzle for introducing samples of the fluid into the flux of diluent gas and for producing a gaseous flux, and a detector for analyzing the gaseous flux, where the source of gas is intended to deliver a flux of diluent gas containing a material capable of supporting the combustion of the inflammable substance, preferably to deliver a flux of air, the injection nozzle is configured so as to introduce into the diluent gas samples of the fluid such that the average volume fraction of the fluid in the gaseous flux is less than 1/2,000 and preferably less than 1120,000, and the detector contains at least one microsensor for detecting the substance to be analyzed.