08-24-2025, 08:30 PM
Function and Importance
NOx (Nitrogen Oxide) sensors are critical components in modern diesel engines, including those in heavy equipment like the Bobcat T870 skid steer. These sensors monitor the concentration of nitrogen oxides in the engine’s exhaust gases. NOx gases are harmful pollutants contributing to smog and respiratory issues, making it vital to accurately detect and reduce them in compliance with environmental regulations.
How NOx Sensors Work
NOx sensors are vital for regulatory compliance and optimal performance in modern heavy equipment engines. Operators of machinery like the Bobcat T870 should source appropriate sensors that match their engine configurations and maintain them to avoid common failures. Rapid access to quality NOx sensors supports machine uptime and environmental responsibility by ensuring emissions are accurately measured and controlled.
NOx (Nitrogen Oxide) sensors are critical components in modern diesel engines, including those in heavy equipment like the Bobcat T870 skid steer. These sensors monitor the concentration of nitrogen oxides in the engine’s exhaust gases. NOx gases are harmful pollutants contributing to smog and respiratory issues, making it vital to accurately detect and reduce them in compliance with environmental regulations.
How NOx Sensors Work
- Installed in the exhaust system, typically both before (upstream) and after (downstream) the Selective Catalytic Reduction (SCR) system.
- The upstream sensor measures NOx emissions directly from the engine exhaust.
- The downstream sensor monitors the efficiency of the SCR system in reducing NOx levels.
- Sensors send real-time data to the Engine Control Module (ECM), which adjusts the injection of diesel exhaust fluid (DEF) accordingly to minimize emissions.
- NOx sensors are subject to contamination by soot and moisture, which can cause sensor failure.
- Faulty NOx sensors may lead to increased DEF consumption, poor fuel economy, failed emissions tests, or engine derate.
- For equipment like the Bobcat T870, NOx sensors are available from various sources, reportedly for less than $2,000 each.
- Replacement involves sourcing the correct sensor matching engine and exhaust system configurations to ensure compatibility.
- NOx sensors have become increasingly stringent with evolving emissions standards, requiring high precision and durability.
- Advances in sensor technology aim to improve accuracy, reduce warm-up time, and resist cross-sensitivity to other gases like ammonia.
- Manufacturers develop sensors specific to engine horsepower and exhaust layout, meaning the same model equipment can require different sensors based on configuration.
- NOx: Nitrogen Oxides, pollutants formed during combustion.
- Selective Catalytic Reduction (SCR): An emissions control system that reduces NOx by injecting DEF into exhaust.
- Diesel Exhaust Fluid (DEF): A liquid used in SCR systems to break down NOx emissions.
- Engine Control Module (ECM): The computer managing engine and emissions control functions.
- Upstream Sensor: Positioned before the SCR system to measure raw engine emissions.
- Downstream Sensor: Positioned after the SCR to monitor emissions reduction efficiency.
NOx sensors are vital for regulatory compliance and optimal performance in modern heavy equipment engines. Operators of machinery like the Bobcat T870 should source appropriate sensors that match their engine configurations and maintain them to avoid common failures. Rapid access to quality NOx sensors supports machine uptime and environmental responsibility by ensuring emissions are accurately measured and controlled.
