Influence of relative humidity on the electrical field strength to promote coalescence between two water drops

This paper describes a determination of the necessary field strengths to induce coalescence between two closely spaced water drops for a range of relative humidities. G.I. Taylor derived an expression for this, but did not consider any effect arising from changes in ambient humidity. Evaporative and other considerations restrict the results to relative humidities of 50% and above. The experimental conditions and apparatus are described together with a discussion of the resulting data. An empirical relationship describing the critical potential difference for coalescence for humidities over 50% for the experimental geometry is presented in the form of correction and scaling factors applicable to Taylorʹs expression.