BAM-G400 (6H)

Certified reference gas mixtures

Certified reference gas mixtures (CRGM) are provided by BAM with compositions and expanded relative uncertainties (k = 2) according to GUM [1] as given in the tables below.

The customer has to provide the starting material and has to demonstrate that the starting material has been synthetically prepared according to ISO 6142 [2] or ISO 6144 [3].

The composition (i.e., amount of substance fractions of the specified analytes) of the starting material is certified with small uncertainty using a measurement procedure according to ISO 12963 [4] or ISO 6143 [5].

Certification of the starting material is carried out against primary standards prepared at BAM according to ISO 6142-1 [2]. By designation from PTB [6, 7], these primary standards are the National Standards of Germany for gas analysis, providing traceability to the International System of Units (SI).

The accordingly certified starting material becomes a measurement standard with transparent SI traceability.

Due to limited preparation capacity, BAM provides gas mixtures according to ISO 6142-1 [2] to customers only in exclusive cases and liable to charges.

Even though the described work on CRGMs at BAM is carried out at BAM in accordance with ISO 17025 [8] and ISO 17034 [9], it is not covered by formal accreditation (yet).

Validity of the issued certificates is usually for a period of two years; exceptions apply for unstable mixtures.

Certified reference gas mixtures comprise:

1. Certified reference gas mixtures for vehicle exhaust emission measurements

especially as defined in PTB-A 18.10 [10]

especially as defined in [11]

related to OIML [12]

1. Certified reference gas mixtures for energy gases

especially as defined in PTB-A 7.63 [13]

1. Binary mixtures
2. Multicomponent certified reference gas mixtures

References:

[1] JCGM 100:2008 “Evaluation of measurement data — Guide to the expression of uncertainty in measurement” (GUM)

[2] ISO 6142-1:2015 “Gas analysis — Preparation of calibration gas mixtures — Part 1: Gravimetric method for Class I mixtures” or upcoming ISO 6142-2

[3] ISO 6144:2003 “Gas analysis — Preparation of calibration gas mixtures — Static volumetric method”

[4] ISO 12963:2017 “Gas analysis — Comparison methods for the determination of the composition of gas mixtures based on one- and two-point calibration”

[5] ISO 6143:2001 “Gas analysis — Comparison methods for determining and checking the composition of calibration gas mixtures”

[6] https://www.bipm.org/en/about-us/member-states/de/cipm-mra.html (accessed June 2020)

[7] PTB Physikalisch-Technische Bundesanstalt is the National Metrology Institute of Germany within the Metre Convention

[8] ISO/IEC 17025:2017 “General requirements for the competence of testing and calibration laboratories”

[9] ISO 17034:2016 “General requirements for the competence of reference material producers”

[10] PTB-Anforderung (Technical Requirement) PTB-A 18.10 „Messgeräte im Straßenverkehr; Abgasmessgeräte für Fremdzündungsmotoren“, PTB, January 2004, DOI: 10.7795/510.20150728T, Section 6.3.3

[11] Section 3.3.3.6 in „Richtlinie zur Kalibrierung von Abgasmessgeräten, die für die Untersuchung der Abgase von Kraftfahrzeugen nach Nummer 6.8.2 der Anlage VIIIa StVZO eingesetzt werden (AU-Geräte Kalibrierrichtlinie)“, rendered on 2018-05-23, Bundesministerium für Verkehr und digitale Infrastruktur, Verkehrsblatt Straßenverkehr Ausgabe Nr. 11/2018

[12] International Recommendation OIML R 99-1 & 2 “Instruments for measuring vehicle exhaust emissions”, International Organization of Legal Metrology (OIML), 2008, Annex B4 and others

[13] PTB-Anforderung (Technical Requirement) PTB-A 7.63 „Messgeräte für Gas; Anforderungen an Kalibriergase für Brennwert- und Gasbeschaffenheitsmessgeräte“, PTB, May 2011, DOI: 10.7795/510.20151109H, addendum published January 2018