Technician level of accreditation (TGPV)
Intended for field technicians who confine their work to inspections and do not prepare verification design or method statements (although they will follow ones prepared by others) and do not prepare verification reports (although they do prepare field records that form part of the verification report.
Specialist level of accreditation (SGPV)
Applies to those involved in the whole range of gas protection verification including design of the verification, preparation of method statements, inspections and verification reports.
Further details including specific competency requirements are listed at: https://www.claire.co.uk/what-is-gpv-accreditation