▁and ▁re ced ing ▁contact ▁angles ▁are ▁measured ▁from ▁dynamic ▁experiments ▁where ▁dro ple ts ▁or ▁liquid ▁brid ges ▁are ▁in ▁movement . ▁In ▁contrast , ▁the ▁equilibrium ▁contact ▁angle ▁described ▁by ▁the ▁Young - La Place ▁equation ▁is ▁measured ▁from ▁a ▁static ▁state . ▁St atic ▁measurements ▁yield ▁values ▁in - between ▁the ▁adv ancing ▁and ▁re ced ing ▁contact ▁angle ▁depending ▁on ▁de position ▁parameters ▁( e . g . ▁velocity , ▁angle , ▁and ▁drop ▁size ) ▁and ▁drop ▁history ▁( e . g . ▁ev ap oration ▁from ▁time ▁of ▁de position ). ▁Contact ▁angle ▁h yst er esis ▁is ▁defined ▁as ▁although ▁the ▁term ▁is ▁also ▁used ▁to ▁describe ▁the ▁expression ▁. The ▁static , ▁adv ancing , ▁or ▁re ced ing ▁contact ▁angle ▁can ▁be ▁used ▁in ▁place ▁of ▁the ▁equilibrium ▁contact ▁angle ▁depending ▁on ▁the ▁application . ▁ ▁The ▁adv ancing ▁contact ▁angle ▁can ▁be ▁described ▁as ▁a ▁measure ▁of ▁the ▁liquid - sol id ▁coh es ion ▁while ▁the ▁re ced ing ▁contact ▁angle ▁is ▁a ▁measure ▁of ▁liquid - sol id ▁ad hes ion . ▁The ▁adv ancing ▁and ▁re ced ing ▁contact ▁angles ▁can ▁be ▁measured ▁directly ▁using ▁different ▁methods ▁and ▁can ▁also ▁be ▁calculated ▁from ▁other ▁wet ting ▁measurements ▁such ▁as ▁force ▁tens i omet ery ▁( aka ▁Wil h emy - Pl ate ▁method ). ▁ ▁Ad van cing ▁and ▁re ced ing ▁contact ▁angles ▁can ▁be ▁measured ▁directly ▁from ▁the ▁same ▁measurement ▁if ▁dro ps ▁are ▁moved ▁linear ly ▁on