As gas chromatography is a comparative method, the final accuracy of the analysed composition, and that of any physical property calculated from it, is principally dependent on the quality of the calibration gas mixture used.
The uncertainty on calorific value can be halved by using a gas mixture which has been calibrated by our UKAS calibration laboratory (ISO 17025) instead of a typical gas mixture supplied direct from a compressed gas manufacturer.  Indeed, the European Union Emission Trading Scheme (EU/ETS) mandates the use of UKAS accredited (ISO17025) calibration gases for on-line process instruments.
Using a primary reference gas mixture, gravimetrically prepared by a metrology laboratory, can marginally improve the uncertainty again but at a vast increase in cost.
Design
Natural gas composition can vary from region to region and also vary on a daily and seasonal basis. EffecTech has experience in designing your calibration gas to meet all your needs. We take into account aspects such as
Variation of delivered composition Operational temperature and pressure Accuracy needed to make it fit for purpose
UKAS accredited certificate of calibration
	EffecTech, through its UKAS accredited calibration laboratory, provides gas mixtures of the highest conformity in terms of traceability, accuracy and stability. We ensure you receive the best solution to your nominal concentration, blend tolerance and analytical uncertainty requirements. Accredited analytical methods are used to provide calibration certificates of the highest standard available in the industry. (See Schedule of Accreditation.)
Use of a calibration gas with our calibration certificate greatly reduces the financial risks that you are exposed to as a result of inaccurate measurement of the energy content of your gas. The extra cost of the certification is negligible compared to your financial exposure.
If you do not require the improved accuracy that a UKAS calibration certificate can give you, we would still recommend that EffecTech designing and providing your calibration gas for you is cost effective.
Delivery and installation
We deliver to site and, if necessary, connect the cylinder, ensuring a leak free installation. We will also update any controllers or integrators and carry out a calibration so that the instrument is ready for use without any delays.
Expertise and experience
You are not only buying our product but also our experience and advice with regard to the use of the reference mixture and the realisation of traceability. The use of the most appropriate calibration gas mixture is only one part of the gas measurement chain. The optimisation of the gas measurement process relies on understanding and deployment of best practice, the use of quality control and getting all other steps of the gas measurement chain correct.
UKAS Schedule of Accreditation - calibration
For our official Schedule of Accreditation issued by UKAS - Click here