Multiplying probe for accurate power measurements on an RF driven atmospheric pressure plasma jet applied to the COST reference microplasma jet

In this paper a new multiplying probe for measuring the power dissipated in a miniature capacitively coupled, RF driven, atmospheric pressure plasma jet (μAPPJ - COST Reference Microplasma Jet - COST RMJ) is presented. The approach aims for substantially higher accuracy than provided by traditionally applied methods using bi-directional power meters or commercially available voltage and current probes in conjunction with digitizing oscilloscopes. The probe is placed on a miniature PCB and designed to minimize losses, influence of unknown elements, crosstalk and variations in temperature. The probe is designed to measure powers of the order of magnitude of 0.1-10 W. It is estimated that it measures power with less than 2% deviation from the real value in the tested power range. The design was applied to measure power dissipated in COST-RMJ running in helium with a small addition of oxygen.