In the last fifty years the composition of natural gas in the Dutch gas grid was very constant. It is expected that the gas quality bands are going to vary much more due to changes of the main gas supply streams in Europe and the increasing use of LNG. Furthermore, the introduction of biogas in the gas grid will lead to a multiplication of the gas injection points. The project aims at the realization of a miniaturized Wobbe index meter for the measurement of the energy content of fuel gases, with most parts integrated on a single silicon chip. Fuel gas and air are heated and mixed on-chip, resulting in spontaneous combustion. The combustion energy is estimated from the resulting elevation in temperature and, combined with density and flow rates measured by also integrated micro Coriolis mass flow sensors, the Wobbe index can be calculated. The micro Wobbe meter is a unique device that can replace existing bulky and expensive Wobbe meters.
Figure 1: Schematic design of the envisioned on-chip energy content measurement system 
See also: http://www.stw.nl/nl/content/integrated-wobbe-index-meter
 J.C. Lötters, T.S.J. Lammerink, M.G. Pap, R.G.P. Sanders, M.J. de Boer, A.J. Mouris, R.J. Wiegerink, R.J. (2013) Integrated micro Wobbe index meter towards on-chip energy content measurement. In: Technical Digest of the 26th IEEE International Conference on Micro Electro Mechanical Systems, 20-24 Jan 2013, Taipei, Taiwan, pp. 965-968. pdf
 R.J. Wiegerink, J.C. Lötters, T.S.J. Lammerink, M.G. Pap, A.J. Mouris, (2012) The application of micro- and nanofluidics in Wobbe index meters. In: Proceedings of the 1st International Conference on Microfluidic Handling Systems, 10-12 October 2012, Enschede, The Netherlands, pp. 166-167. pdf
 J.C. Lötters, E.J. van der Wouden, J. Groenesteijn, W. Sparreboom, T.S.J. Lammerink, R.J. Wiegerink (2014) Real-time composition determination of gas mixtures. (Invited) In: Proceedings of IEEE Sensors 2014, 2-5 Nov 2014, Valencia, Spain, pp. 1640-1643. pdf