Cold atmospheric pressure plasma consisting of OH, O, O3, NO, and NO2 radicals is currently popular in biomedical applications. This is due to its ability on destroying microbes and stimulating on production of new cells. In this work, we have applied ultraviolet (UV) absorption spectroscopy with micro stage XY table add-on for adjustment of radial distance to investigate and measure the density of hydroxyl (OH) in the needle-typed cold atmospheric-pressure plasma jet and dielectric barrier discharge (DBD) plasma and their radial concentration distribution on a surface, which these plasma jets were generated by various argon gas flow rate. Principles and procedures of the UV-absorption spectroscopy technique as well as the experimental results will be reported and discussed in this contribution.
Keyword: OH radical, UV-absorption spectroscopy, Cold atmospheric pressure plasma.