An interrogation system of fiber Bragg grating sensors using time division multiplexing and wavelength division multiplexing is proposed and demonstrated. The system presents a solution to measure the magnitudes associated to the reflection spectrum of the fiber Bragg gratings, making possible to increase the number of the Bragg gratings sensors monitored through large distances at the same fiber optic, without a great increase in the costs. The innovative aspect of this system is the particular association of the following characteristics: the use of a pulsed broad band source, the disposition, in series, of a large number of low reflectivity Bragg gratings sensors, the reusing technique of the same nominal wavelengths in groups containing several numbers of sensors with distinct nominal wavelengths, and a spectral analyzing and filtering process of pulsed signals using a commercial DWDM filter. Theoretical and experimental aspects regarding the working principles of this technique are discussed. Comparisons between experimental and simulated results show a good agreement. Experimental results indicate that a dynamic range of 1,7 nm was obtained. It can be used in temperature measurement systems, with a 150°C range. Uncertainties equivalent to approximately 20 picometers was obtained. Experimental simulations indicate that it would be possible to use a number of approximately 70 sensors with 0,4% reflectivity at each nominal sensor wavelength. Considering the DWDM filter bandwidth (1539-1565 nm) used in this system, and a spectral separation of 7 nm by nominal sensor wavelength, extrapolations indicate that a number of 210 sensors can be obtained, in three different nominal sensor wavelength. Using the C-band and the L-band, a number of 1000 sensors can be obtained, in fourteen different nominal sensor wavelength.