scale 3 
(skāl)
(skāl)n.
1. An instrument or machine for weighing.
2.
a. often scales See balance.
b. Either of the pans, trays, or dishes of a balance.
v. scaled, scal·ing, scales
v.tr.
To weigh with a scale.
v.intr.
To have a given weight, as determined by a scale: cargo that scales 11 tons.
[Middle English, bowl, balance, from Old Norse skāl; see skel-1 in the Appendix of Indo-European roots.]