Patent ID: 8689605
Filing Date: 2014-04-08
Classification: F23N,G01N

Abstract:
1. A process gas transmitter comprising: a probe assembly configured for exposure to combustion exhaust within a flue, the probe assembly including a diffuser, a measurement cell and a heater disposed proximate the measurement cell to heat the measurement cell to an operating temperature, wherein the operating temperature is at least as high as a flashpoint of fuel of the combustion; an electronics board operably coupled to the probe assembly, the electronics board being configured to obtain process gas measurements from the measurement cell while the measurement cell is at the operating temperature; a pneumatic valve fluidically interposed between a source of purge gas and a calibration gas inlet of the probe assembly, the pneumatic valve being operably coupleable to an input wherein the pneumatic valve allows flow of purge gas from the source to a location in the probe assembly between the measurement cell and the diffuser when a signal at the input indicates a condition; and wherein the input is a flame scanner input and the condition is a flameout condition.