The range extends from stable, traceable mixtures for calibration of sensitive emission analysis equipment to high purity air, fuel gas and nitrogen.
Alpha Standards
Alpha standards are used as the primary calibration gases in measuring emission rates as determined by statutory test procedures laid down by many countries including the United States, Europe and Japan. These standards are manufactured and certified to within +/- 1% of the stated value of international Secondary Reference Material (SRM) such that issued by the National Institute for Standards and Technology (NIST) or National Physical Laboratory (NPL).
The stability of the standard with respect to time (shelf-life), temperature and pressure variations is vital if the calibrations for vehicle testing are to be accurate. Alpha standards containing reactive gases are produced using BOC's proprietary Spectra-Seal passivation process for guaranteed stability over 5 years.
Multi-component Traceable Standards
BOC has spearheaded the development of traceable, multi-component gas standards in the Alpha and Beta ranges. It is now possible to provide 3, 4 or 5 gas mixtures containing typical emission components with direct traceability to SRM and with an analytical tolerance of +/- 1% or +/- 2%.
If you have a requirement for multi component traceable standards please contact BOC Speciality Gases on 1800 355 255 or email specialproducts@boc.com
BTCA and others
The British Technical Council for the petroleum and motor industries specifies gas mixtures for instrument calibration. These mixtures are analysed to +/- 2% and are all supplied with a certificate. These mixtures are normally used as day-to-day span gases for instrument calibration.
BTCA mixtures list
122943-L-C | BTCA 74 | Artificial air HC's<1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
345074-V-C | BTCA 74 | Artificial air HC's<1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
122944-L-C | BTCA 178 | Artificial air HC's<1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
345178-V-C | BTCA 178 | Artificial air HC's<0.1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
345075-L-C | BTCA 75 | Nitrogen HC's<1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
110176-V-C | BTCA 75 | Nitrogen HC's<1vpm, CO<1vpm, CO2<300vpm, NOx<0.1vpm | |
290562-L-C | BTCA 179 | 40% Hydrogen / balance Helium | |
290562-AV-C | BTCA 179 | 40% Hydrogen / balance Helium | |
110955-L-C | BTCA 270 | Oxygen |
(BTCA Low Emission Gases are the gases suggested by the BTC for emission testing of cars to comply with current and future regulations).
MOT test and engine tuning mixtures
On 1st November 1991 new regulations came into force requiring a check of carbon monoxide and hydrocarbon exhaust emissions for all petrol engine vehicles as an additional part of the current MOT test.
The MOT exhaust emission test legislation requires that the machine used to test the vehicles is type approved by the DTLR. In addition the machine must be calibrated using a Certified Reference Standard produced in accordance with ISO/IEC 17025. BOC is the only supplier accredited by UKAS to ISO/IEC 17025 as a Calibration Laboratory (0408) for the supply if these certified reference standards.
Contact BOC Speciality Gases on 1800 355 255 or email us