Gas


The Gas Laboratory develops, maintains and disseminates gas metrology related national measurement standards in Singapore. NMC has set up and is continuously improving national standards through R&D activities in this area to better meet the need of the industry. We have also participated in international comparisons to ensure our gas standards are equivalent to those of other countries.

Standards and capabilities:
 Preparation of Gas Standards
 Gas Analysis
 
Ozone Measurement and Standard [Brochure]
 Measurement Solutions and Certified Reference Mixtures (CRMs)

For the list of the Certified Reference Mixtures (CRMs), please click here.

Preparation of Gas Standards

  • Gravimetric method

    Gas standards are prepared by gravimetric method based on ISO 6142:2001(E) within the concentration range of 10 x 10-6 to 0.9 mol/mol (10 ppm to 90%).

  • Dynamic method

  • NMC is developing a new capability in preparing gas mixture using dynamic method to produce reference gas mixtures with various concentrations. This is very useful for characterisation of gas sensors.

Measurement Solutions and Certified Reference Mixtures (CRMs)

NMC provides calibration of various gas analysers and gas sensors using our primary reference gas mixtures. We also produce Certified Reference Mixtures (CRMs). These CRMs are prepared gravimetrically in accordance with ISO 6142 and are validated against in-house Primary Standard Gas Mixtures (PSMs).

 

Vehicle Exhaust Control

Vehicle emissions regulations dictate that emission gases are routinely measured to accurate standards. Thus traceable gas mixture standards are required for calibration of instruments. Automotive test gases are available from NMC in the ranges prescribed in OIML recommendation R99 “Instruments for measuring vehicle exhaust emissions”. The gas mixture components and their concentration range are given below.



 

Ship Emission Gas

IMO (International Maritime Organization) requires the reduction of the combinations of sulphur oxide (SOx), carbon dioxide (CO2) and nitrogen oxide (NOx) from shipping and floating vessels be less than 0.1% by 2015. To reduce sulphur dioxide (SO2) emissions, ships could possibly use Exhaust Gas treatment systems such as a sulphur dioxide scrubber system. For the assurance of compliance and traceability, accurate measurement and calibration of SO2 detectors need traceable certified reference gas mixture. NMC’s gas laboratory is able to provide following gas standard to help the maritime industry to comply with IMO regulation on gas emission.

 

Volatile organic compounds (VOCs)

VOCs can have harmful effects on indoor air quality (IAQ), ecosystems and human health. There is a need to reduce the VOCs’ effects on the public and the environment. Stable and accurate VOC gas mixtures are needed to facilitate the traceable calibration of analytical instrumentation. NMC is developing capabilities to prepare VOC reference mixtures for IAQ monitoring and gas sensor characterization.



Energy gases

NMC is developing natural gas standards which can be used to calibrate natural gas analysers. Composition of natural gases need to be determined with high accuracy to have accurate calculation of the calorific value. Composition measurement will cover C1 to C10 components. Accurate measurement of the heavy hydrocarbon components is useful to determine hydrocarbon dew point with high accuracy, which is important to avoid condensation of the gas mixture during transportation via the gas pipeline.

 



Ozone Measurement and Standard

Ground-level ozone (or tropospheric ozone) is an atmospheric pollutant. It is not emitted directly by car engines or industrial operations but formed by the reaction of sunlight on air containing hydrocarbons and nitrogen oxides that react to form ozone directly at the source of the pollution or many kilometers down wind. Ozone reacts directly with some hydrocarbons such as aldehydes and thus begins their removal from the air, but the products become key components of smog.

NMC has established the first primary ozone measurement facility in South-East Asia based on Standard Reference Photometer (SRP 46) and has capabilities for the calibration of ozone analyzers in the range of 0 to 500 nmol/mol.

Gas Analysis

  • Gas analysis capabilities

    Gas analyzers with various detectors, e.g., Ultra-violet (UV), Non-dispersive infrared absorption (NDIR), Paramagnetic, Potentiometric, Standard Reference Photometer and Gas Chromatography.

 

  • Purity Analysis

    1. Multi-component gas analyser based on Cavity Ring Down Spectroscopy (CRDS) for trace concentrations of H2O, O2 , N2, H2, He and Ar.


  • 2. Gas chromatography with PDHID and FID for purity analysis of N2, O2, H2, He, Ar, CO, CO2 and CxHy