Wideband vs. narrow band sensor

Wideband vs. narrow band sensor

A wideband oxygen sensor is a sensor that measures the ratio of oxygen to fuel vapour in the exhaust leaving an engine. The measured ratio is expressed as parts of oxygen to fuel. If there is 15 parts of oxygen to every one part of fuel, this would be expressed as an air/fuel ratio of 15 to 1, or 15.0:1 or to be exact 14.7kg of air equals to 1kg of fuel. For CNG the ratio is 16.2:1. The wide means the air/fuel ratio can be measured at a very far-reaching range (often from around 5:1 up to around 22:1).

Wideband sensor installation:

There are three parameter/variable should be considered when using a wideband sensor;

1. Accuracy is top priority. If the wideband's readings are inaccurate, you may make fuel adjustments in error resulting in a loss of power or even worse, engine damage.

2. Speed. The wideband must be responsive to changes in air/fuel ratio to allow accurate fuel adjustments for changes in engine rpm and load.

3. Ease of installation/ Compatibility. The wideband oxygen sensor must be compatible with your tuning software, hardware, and installation needs.

 http://www.hamotorsports.com/what-is-a-wideband.html

Narraow band: 

NARROW-BAND sensor) can only measure the air/fuel ratio over a very narrow range (often from only around 14.5:1 up to 15.0:1).

Effect of Extreme Temperatures on Coated Piston Crown for CNG direct injection

Effect of Extreme Temperatures on Coated Piston Crown for CNGDI Engine..clear and concise

Due to high temperature and less proper heat transfer, the material of piston crown in an engine of compressed natural gas with a direct injection system (CNGDI) may lead to high thermal stresses and fails to withstand high temperature and operate effectively. By insulating with thermal barrier coating (TBC) such as ceramic-based yttria partially stabilised zirconia (YPSZ), heat transfer to the piston might be reduced and lead to improvement of piston durability. Hence, in this research, YPSZ coating was utilised to differentiate with the uncoated piston crowns in terms of the ability to reduce thermal penetration to the piston. A detailed finite element analysis (FEA) was carried out to determine the location of hotspots via profiles distribution of thermal. In short, it was observed that hotspots were mainly concentrated at the piston bowls rim. The heat flux for the YPSZ/NiCrAl-coated from FEA exhibited about 98% reduction compared to the uncoated piston crown.

full article :  http://www.scientific.net/AMM.393.281