Letter 30038 Ring-plate vs. bubble pressure   ++++ I am not familiar with the method of bubble pressure for surface tension measurements. Is it as sound as the ring-plate method? Any major disadvantages? My application is the daily testing of surface tension in a Nickel Sulfamate bath. Chad Nicewonger Plating shop - Titusville, PA, United States ++++ The Bubble Pressure Method gives you a dynamic surface tension. Unlike the static methods by plate or ring new surfaces will be generated with each bubble. The lifetime of the bubble can be controlled depending of the instrument in a range of ms up to 100s. This way time-dependent surface tension values can be obtained. This is especially from interest in fast wetting processes. Further advantage of up to date bubble pressure tensiometer is the easy handling in comparison to Static Tensiometer (Cleaning and Calibrating). Surfactant concentration in metal cleaning baths or galvanic baths can be monitored in a broad surfactant concentration range (also above the CMC). A new hand-held instrument is now available for a short time. Veit Huber - Dresden, Saxony, Germany Dear Reader: please choose what you want to do-- I want to Answer or follow-up on this subject publicly (in non-commercial fashion).   I want to post a new question or inquiry of my own on a different subject.