Editing Weighing scale (section)

==Hybrid spring and balance scales==
[[File:Elastica arm scale.jpg|thumb|A prototype of an elastic arm scale measuring a mass]]

===Elastic arm scale===
In 2014 a concept of hybrid scale was introduced, the elastically deformable arm scale,<ref>{{cite journal |url=http://www.ing.unitn.it/~bigoni/paper/elastic_scale_bosi_misseroni_dalcorso_bigoni.pdf |doi=10.1098/rspa.2014.0232|pmid=25197248|pmc=4123770|title=An elastica arm scale|journal=Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences|volume=470|issue=2169|pages=20140232|year=2014|last1=Bosi|first1=F.|last2=Misseroni|first2=D.|last3=Dal Corso|first3=F.|last4=Bigoni|first4=D.|bibcode=2014RSPSA.47040232B|arxiv=1509.06713}}</ref> which is a combination between a spring scale and a beam balance, exploiting simultaneously both principles of equilibrium and deformation. In this scale, the rigid arms of a classical beam balance (for example a [[Steelyard balance|steelyard]]) are replaced with a flexible elastic rod in an inclined frictionless sliding sleeve. The rod can reach a unique sliding equilibrium when two vertical dead loads (or masses) are applied at its edges. Equilibrium, which would be impossible with rigid arms, is guaranteed because [[Configurational mechanics|configurational forces]] develop at the two edges of the sleeve as a consequence of both the free sliding condition and the nonlinear [[kinematics]] of the elastic rod.  This mass measuring device can also work without a [[counterweight]].