Certified Calibration Standards vs Primary Gravimetric Standards

BOC Limited
Monday, 06 September, 2021

BOC’s world-class laboratory allows for a database of over 5,000 individual mixtures, all designed to ensure that the final product is fit for purpose. BOC’s calibration standards represent the most diversified range of products from BOC. This range is split into two main categories: HiQ^® CERTIFIED CALIBRATION STANDARDs and HiQ PRIMARY GRAVIMETRIC STANDARDs. Outlined below are the differences between both as well as how to choose which mixture is best for you.

HiQ CERTIFIED CALIBRATION STANDARDs can be prepared using weight, pressure or volumetric techniques. Technical staff determine the most appropriate preparation method based on the properties and composition of the mixture. HiQ CERTIFIED CALIBRATION STANDARDs are analytically compared to reference standards in accordance with ISO 61433 using a range of validated and approved methods. This provides you with an unbroken chain of traceable measurements to the national standard of mass or primary reference materials from National Metrology Institutes.

HiQ PRIMARY GRAVIMETRIC STANDARDs are produced by weighing high purity, analysed raw materials into a cylinder or container using high capacity, high accuracy balances. These balances are regularly calibrated by NATA accredited calibration laboratories ensuring our HiQ PRIMARY GRAVIMETRIC STANDARDs are traceable to the national standard of mass. The composition of the mixture is calculated from the component masses and known raw material purity. The resulting mixture accuracy is very high and is in compliance with ISO 61424. Higher levels of accuracy and precision are achievable with gravimetric methods when compared to traditional methods of preparation.

HiQ PRIMARY GRAVIMETRIC STANDARD	HiQ CERTIFIED CALIBRATION STANDARD
→ ISO 34 accredited	→ ISO 34 accredited
→ ISO 6142 compliant	→ ISO 6143 compliant
→ Exclusively filled using gravimetric techniques	→ Filled using volumetric, manometric (pressure) or gravimetric techniques
→ For critical applications such as custody transfer	→ For calibration of on-line instrumentation, process monitoring or non-critical analysis
→ Gravimetric values quoted on certificate with analytical verification	→ Analytical results quoted on certificate
→ NATA1 or IANZ2 endorsed Certificate of Analysis, ISO 6142 or heating value report provided on request	→ NATA1 or IANZ2 endorsed Certificate of Analysis

Which mixture is best for me?

These HiQ gas mixtures are formulated by BOC’s experienced technical team who can also assist you with traceable and accreditation materials right for your business. If you need accuracy and precision for critical applications, a HiQ PRIMARY GRAVIMETRIC STANDARD is recommended. For other applications where minor deviations in filling tolerance or wider certification windows are acceptable, a HIQ CERTIFIED CALIBRATION STANDARD is recommended.

For more information, please visit https://www.boc-gas.com.au/ or email our dedicated Customer Service Centre at scientific@boc.com.