Abstract: Combustion variables are diagnosed using sensors to measure turbulence in the post-flame zone as well as in the flame envelope of a combustor. Output signals from the sensors are processed and a set of statistical functions are calculated which are correlated with specific combustion variables, such as the concentration of unburned carbon in fly ash. A special sensor mounting box provides reliable long-term operation in harsh combustor environment, without a supply of cooling or protective air flow.

Abstract: Combustion variables are diagnosed using sensors to measure turbulence in the post-flame zone as well as in the flame envelope of a combustor. Output signals from the sensors are processed and a set of statistical functions are calculated which are correlated with specific combustion variables, such as the concentration of unburned carbon in fly ash. A special sensor mounting box provides reliable long-term operation in harsh combustor environment, without a supply of cooling or protective air flow.

Abstract: In one embodiment, a gas-sensing probe for use in a combustor includes an elongated support member, a housing, a gas sensor and sensor wires. The housing is attached to an end of the support member, and the gas sensor is rigidly supported within the housing. In another embodiment, a gas-sensing probe for use in a combustor includes an elongated support member, a housing, and a gas sensor. The housing is removably attached to an end of the support member, and the gas sensor is disposed within the housing so that the gas sensor and housing are removable from the distal end of the support member as a unit. In another embodiment, a gas-sensing probe comprises an elongated support member, a gas sensor, and a calibration tube. The elongated support member has a proximal end and a distal end, and supports the gas sensor at the distal end thereof.

Abstract: A Nernstian-type gas sensor for monitoring changes in a concentration of oxygen present in an environment. One embodiment includes a mass of solid-electrolyte material, and first and second electrodes. The first and second electrodes are each in fluid communication with the environment and are arranged to generate a signal therebetween indicative of a difference between an oxygen concentration at the first electrode and an oxygen concentration at the second electrode. The sensor may be free of a temperature control device.

Abstract: An amplifier having at least a pair of gain levels for each of the AC and DC components of an input signal. The non-linearity in gain is achieved through the use of feedback which varies, in stepwise fashion, with input sigal magnitude.