stalagmometer

noun

stal·​ag·​mom·​e·​ter ˌstal-ag-ˈmäm-ət-ər 

: a device for determining the number of drops in a given volume of liquid especially for use in calculating the surface tension (as of blood or serum)

stalagmometric

stə-ˌlag-mə-ˈme-trik 

adjective