For transmission companies, this high accuracy ensures that the international standards of gas quality for transport and use are met.

These pipeline networks are highly complex transmission and distribution systems used to move gas across states, countries or even continents. In all of these cases it is important that gas quality is maintained within the requirements of the main international natural gas quality harmonization guidelines. These guidelines include moisture content and in Europe, the EASEE-gas Common Business Practice – 2005-001/01 – Harmonisation of Natural Gas Quality sets a water dew-point limit of -8°C at 70 barg,equal to a moisture content of ~49 ppmV (based on ISO18543).

Taking advantage of the latest developments in laser spectroscopy, the OptiPEAK TDL600 has an unrivalled accuracy for any process moisture analyzer of ±1% of the reading or 1ppmV verified by calibration traceable to NPL (UK) and NIST (US). Its lower detection limit of 1ppmV makes it the most sensitive instrument in its class on the market, as well as being one of the most reliable. Michell has developed a unique laser lock system to ensure the laser remains locked to the correct water absorption signal, maintaining a high integrity measurement at all times. In some earlier TDLAS moisture analyzer designs, drift in laser wavelength over time may cause gradual deterioration in measurement performance.

With D-MET, the Dynamic Methane Compensation System, the OptiPEAK TDL600 is also able to measure moisture reliably in natural gas with varying compositions (such as blended gas from multiple fields or following bio-methane or re-gasified LNG injection) without the need for manual software correction factors to be made.

Michell Instruments

Tel – +44(0)1353 658 000