Sampling Spark Plug

In-cylinder Gas Measurements

Measurements of gas emissions with fast response analysers in the exhaust port of an engine can offer cycle by cycle information about post-combustion concentrations. The need often arises to measure the pre-combustion concentration of species. Pre-ignition HC measurements in a spark ignited engine may be used to improve fuelling accuracy, particularly at cold start where vaporization is poor. In-cylinder CO₂ measurements may be used to measure the combination of any external EGR and trapped residuals, and are particularly valuable when calibrating EGR strategy or Variable Valve Timing.

The Sampling Spark Plug Accessory

All of the Cambustion fast response gas analysers can be used with the Sampling Spark Plug accessory. This uses an offset spark plug with a threaded access port to allow the connection of a sampling line for gas extraction. A range of different reach, thread, seat configurations and temperature ratings are available.