A Reconfigurable Parallel Data Acquisition System for Tunable Diode Laser Absorption Spectroscopy Tomography

The design of the data acquisition instrument directly affects the temporal resolution of laser absorption spectroscopy (LAS) tomographic system. In this paper, a parallel data acquisition system was designed and applied to collect 60 channels of absorption light intensity data. In the design, the data collecting process and the data uploading process were bridged by adding memory chips on data acquisition circuits. The temporal resolution of fan beam parallel acquisition LAS tomographic system was thus reconfigurable to 1-8k frames/s and the data from 60 channels for each frame was synchronized. Experiment results were implemented on an acoustic excitation impulse flame burner, and H₂O was chosen as the target absorbing species for the laser absorption. Temperature distributions for the excitation cycles were reconstructed and presented. The system performances at different working frame rates were compared, and it had a high temporal resolution of up to 8k frames/s.