NH3 absorption line study and application near 1084.6 cmcm−1

•Develop a Mid-IR QCL spectrometer coupled with two reactors (gas cell and shock tube) running in three modes (140 Hz, and 10 kHz scan modes, and fixed-wavelength mode)•Examine adsorption effects of NH3 in the shock tube.•Measure high-quality NH3-Ar pressure broadening coefficients and spectrally resolved cross-section datasets near 1084.6 cm−1 for the first time.•Quantify tiny high-temperature water absorption interference near 1084.6 cm−1 using a near-infrared water laser.•Quantify NH3 mole fraction of oxidation process in the shock tube and compare to simulations as an application scenario.