A laboratory experimental work is carried out to investigate the attenuatio
n ability of water sprays subjected to thermal radiation. The objective is
to analyze the key parameters involved in the mitigation properties of this
fire protection technique. The spectral transmittances of two types of spr
ayers, TG03 and TG05, are measured with a Fourier infrared spectrometer und
er various conditions. The wavelength range varies from 1.5 to 12 mum. The
influence on the transmittance of both the flow rate and the pressure rangi
ng from 1 to 7 bars, as well as the effect of the number of spray nozzles a
re considered. The results clearly show the advantage of small drops with h
igh concentration. An investigation on the multi-ramp curtain configuration
also provides valuable information on the mitigation behavior of the whole
spray. Key guidelines are provides for fire protections engineering.