Wobbe index sensor system

A system for measuring Wobbe index of a fuel comprising:

• a flow control device configured to control at least one of a flow rate of air and a flow rate of a fuel for providing a combustible air-fuel mixture;
• a first sensor in flow communication with said flow control device, said first sensor comprising:
• a first substrate;
• a first diaphragm layer comprising:
• a first layer comprising at least one heating element configured to sense energy content in the fuel, the at least one heating element comprising a doped poly-silicon carbide layer that is disposed on the substrate;
• and
• a second layer comprising an undoped poly-silicon carbide layer configured to prevent oxidation of the first layer;
• and
• a first cavity formed under the first diaphragm layer and configured to provide thermal isolation of the t least one heating element;
• a second sensor in flow communication with said flow control device, said second sensor comprising:
• a second substrate;
• a second diaphragm layer comprising:
• a first layer comprising a plurality of heating elements configured to sense energy content in the fuel, the plurality of heating elements comprising a doped poly-silicon carbide that is disposed on the second substrate;
• a second layer comprising an undoped poly-silicon carbide layer configured to prevent oxidation of the first layer;
• a sensing layer comprising a catalyst and disposed on the second diaphragm layer;
• and
• a second cavity formed under the second diaphragm layer configured to provide thermal isolation of the heating elements;
• and
• a sensor exhaust in flow communication with said sensor and configured to measure a volumetric flow rate of combustion products.