  Instruments play an essential role in creating research data. Given the
importance of instruments and associated metadata to the assessment of data
quality and data reuse, globally unique, persistent and resolvable
identification of instruments is crucial. The Research Data Alliance Working
Group Persistent Identification of Instruments (PIDINST) developed a
community-driven solution for persistent identification of instruments which we
present and discuss in this paper. Based on an analysis of 10 use cases,
PIDINST developed a metadata schema and prototyped schema implementation with
DataCite and ePIC as representative persistent identifier infrastructures and
with HZB (Helmholtz-Zentrum Berlin f\"ur Materialien und Energie) and BODC
(British Oceanographic Data Centre) as representative institutional instrument
providers. These implementations demonstrate the viability of the proposed
solution in practice. Moving forward, PIDINST will further catalyse adoption
and consolidate the schema by addressing new stakeholder requirements.
