What is BS EN ISO 1938-1- Geometrical product specifications (GPS). Dimensional measuring equipment about?
BS EN ISO 1938-1:2026 is the latest revision of the international standard for plain limit gauges used to verify linear dimensional specifications associated with linear size. It defines the different types of plain limit gauges and sets out their design and metrological characteristics, including maximum permissible limits for both new and worn states.
Used widely across manufacturing and engineering, plain limit gauges provide a fast and reliable pass or fail assessment, helping organizations confirm whether components meet specified tolerance limits. It reflects international expert input to ensure the requirements remain clear, consistent and aligned with current industry practice.
Who is BS EN ISO 1938-1- Geometrical product specifications (GPS). Dimensional measuring equipment for?
This standard is intended for anyone involved in the verification of linear dimensional specifications. It is particularly relevant to:
- Mechanical engineers.
- Quality control and verification personnel.
- Inspection officers.
- Metrologists.
- Measuring equipment manufacturers and suppliers.
- Measuring instrument users.
- Laboratories that test and calibrate measuring equipment.
It is applicable across a wide range of sectors including aerospace, defence, automotive, nuclear, rail and general manufacturing.
What does BS EN ISO 1938-1- Geometrical product specifications (GPS). Dimensional measuring equipment cover?
BS EN ISO 1938-1:2026 covers plain limit gauges used to verify linear sizes of up to 500 mm for rigid workpieces. The standard defines:
- Types of plain limit gauges.
- Design characteristics of limit gauges.
- Metrological characteristics and requirements.
- Maximum permissible limits for new and worn gauge states.
- Guidance on the correct use of limit gauges.
It also includes additional gauge forms to support consistent verification across different applications.
Why should you use BS EN ISO 1938-1- Geometrical product specifications (GPS). Dimensional measuring equipment?
Using BS EN ISO 1938-1:2026 helps you ensure that your dimensional verification processes are based on up to date, internationally agreed requirements. The standard supports consistency, accuracy and confidence in inspection results, helping you reduce the risk of non conforming parts, rework or disputes.
For organizations using plain limit gauges, adopting the latest revision helps maintain alignment with global best practice and provides clarity around gauge design, performance and permissible wear limits.
What’s changed?
BS EN ISO 1938-1:2026 is the latest edition and supersedes BS EN ISO 1938-1:2015. It introduces several technical updates compared with the 2015 edition, including:
- Revised definitions to improve clarity.
- Updated design and metrological characteristics for GO gauge types B to K.
- The inclusion of full form cylindrical ring, full form notch gauge and gap gauge in Table B.1.
These changes help improve understanding, consistency and application of the requirements for users of plain limit gauges