New Calibration Method for Kelvin Probe in Changing Humidity Conditions. Issue 10 (1st October 2022)

• Record Type: Journal Article
• Authors: Seeger, Lea; Lobnig, Renate; Wicinski, Mariusz
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 10(2022)
• Publication Date: 2022-10-01
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac8fbc
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The use of the Kelvin probe (KP) to determine Ecorr values is based on the relationship E corr = const. + ΔΨ (with ΔΨ = measured value of the KP and const. = constant). The constant const. is determined by calibration above a reference sample with known Ecorr . It has been shown that the constant const. can vary by up to 172+/−18 mV with a probe of nickel and 178 μ m probe diameter, when the relative humidity RH varies between 42% and 98%, which must be taken into account when making measurements under changing climatic conditions. It has been shown, theoretically and experimentally, that the RH at the probe tip 40 μ m above a saturated salt solution is nearly equal to its critical relative humidity. An experimental procedure is proposed to determine the dependence of const. on RH. For this purpose 4 Cu/saturated Cu-salt half-cells are used. Additionally, a method is proposed to measure the critical relative humidity of a saturated salt solution using KP.