Measuring component concentration in a gas blend

Method for measuring the thermal conductivity in a gas blend in order to determine and measure concentration of components of and in that blend comprising:

• the steps of
• (i) producing a sensor being comprised of a Silicon carrier being a few hundred micrometers thick and being provided with an electrically insulating layer, there being a sputtered on or vapor deposited meander shaped thin film resistance on the insulating layer;
• a pit in said carrier underneath said resistance and said insulating layers, there being at least one perforation in the insulation to permit access of gas to the interior of the pit;
• a cover plate made also of Silicon of comparable thickness dimensions as the carrier and also having a pit of comparable dimensions as the first mentioned pit, the cover plate being disposed above said carrier so that said pits are aligned and constitute a common measuring chamber;
• a diffusion channel in the cover plate for feeding a gas through diffusion so that a measuring chamber is defined by the combined communicating pits;
• and
• (ii) measuring the thermal conductivity in said blend at a number of different temperatures, using said sensor whereby for n different components at least n-1 different measurements are made at n-1 different temperatures.