EGR distribution and fluctuation probe based on CO₂measurements

摘要

A diagnostic system having a single-port EGR probe and a method for using the same. The system includes a light source, an EGR probe, a detector and a processor. The light source may provide a combined light beam composed of light from a mid-infrared signal source and a mid-infrared reference source. The signal source may be centered at 4.2 μm and the reference source may be centered at 3.8 μm. The EGR probe may be a single-port probe with internal optics and a sampling chamber with two flow cells arranged along the light path in series. The optics may include a lens for focusing the light beam and a mirror for reflecting the light beam received from a pitch optical cable to a catch optical cable. The signal and reference sources are modulated at different frequencies, thereby allowing them to be separated and the signal normalized by the processor.

主权项

1. An apparatus for determining CO2 concentrations in a fluid stream, the apparatus comprising:
a combined light source affixed to a first end of an pitch optic cable, the combined light source having a probe LED producing light in a first portion of the MIR spectrum including significant CO2 absorption features; and a reference LED producing light in a second portion of the MIR spectrum not including significant CO2 absorption features; a lens disposed proximate a second end of the pitch optic cable for directing the combined light source through a sampling chamber to a mirror; a catch optic cable having a second end disposed proximate said lens; and a catch optic affixed to a first end of said catch optic cable.