The zygostates (Greek: ζυγοστάτης, "one who weighs with a balance"; plural: ζυγοστάται, zygostatai) was a public weigher of the coinage of the Byzantine Empire.
[1] The Byzantine emperor Justinian I (r. 527–565) regarded the zygostatai, in his 11th Edict, as the main offenders in changing the purity of gold coins.
[1] Based on this evidence, John Bagnell Bury surmised that in the 7th century the zygostates began to examine and weigh coins that came to the Byzantine imperial treasury.
[1] The Byzantine Greek monk and abbot, Theodore the Studite, described the zygostasia, or the imperial station where the zygostatai worked, as a profitable business.
[1] The term zygastikon (Greek: ζυγαστικόν), attested in a false privilege granted to the city of Monemvasia in 1316, refers to one of the customary payments made to toll inspectors for measuring and weighing wares.