Gauge Block Calibration Services
Calibration of gauge blocks by interferometry.
NPL services for interferometric (Class A) calibration of gauge blocks
Gauge blocks are among the most commonly used standards for maintaining traceability in engineering. Before use, all gauge blocks must themselves be calibrated according to various specification standards such as BS 4311, BS EN ISO 3650, and ISO 3650. Gauge blocks must also be re-calibrated periodically to maintain their accuracy. In order to satisfy these requirements NPL offers a comprehensive UKAS-accredited calibration service for gauge blocks from 0.5 mm to 1000 mm in length. This service is available by prior booking.
Calibration service details
NPL's gauge block calibration service offers the following features:
- interferometric calibration of central length
- verification of measurement face flatness
- verification of variation in length
- interferometric calibration of coefficient of thermal expansion (lengths over 100 mm)
- calibration to ISO 3650, BS 4311, BS EN ISO 3650
- calibration of steel, tungsten carbide or ceramic gauge blocks
Download flyer outlining Gauge Block measurement services available (
PDF 128 KB)
Gauge block types we can calibrate for you
NPL can measure the following grades of gauge block:
- Grades K, 0 of (BS EN) ISO 3650
- Grades K, 0 of BS 4311 (2007)
- Grades Calibration, Reference, 00, 0 of BS4311 (1968) and BS 888
- Grade 1 of (BS EN) ISO 3650 (by mechanical comparison)
A PDF note on the types of gauge blocks we can measure ( PDF 281 KB) is also available.
Measurement uncertainty
Gauge block central length measurement uncertainty: ±[0.019, 0.00021L] µm at 95 % confidence level (where L is the length of the gauge in mm).
NPL's gauge block services are covered by the CIPM MRA and are UKAS-accredited.
Further information
- Contact us for more details, to request a quotation or to schedule a calibration
- Details of thermal expansion measurements on long gauge blocks
- Notes on the care and use of gauge blocks ( PDF 18 KB)
Publications
- Lewis, A J, Long-term study of gauge block interferometer performance and gauge block stability, Metrologia, 2010, 47, 473-486
- Lewis, A J, Measurement of length, surface form and thermal expansion coefficient of length bars up to 1.5 m using multiple-wavelength phase-stepping interferometry, Meas. Sci. Technol., 1994, 5, 694 – 703
- Lewis A J, Pugh D J, Interferometer light source and alignment aid using single-mode optical fibres, Meas. Sci. Technol., 1992, 3, 929-930
- Lewis A J, Absolute length measurement using multiple-wavelength phase-stepping interferometry, PhD Thesis, 1993, Imperial College, University of London
- Lewis A J, Key Comparison CCL-K2 – Measurement of long gauge blocks – Final Report, Metrologia, 2003, 40 Tech. Suppl. 04004
- Lewis A J, Final Report on EUROMET Key Comparison EUROMET.L-K2: Calibration of long gauge blocks, Metrologia, 2006, 43 Tech. Suppl. 04003
Contact
Customer Service tel: 020 8943 8631
E-mail: dimensional_enquiries@npl.co.uk