An engine oil quality sensor is an electrical device that measures the amount of _________________ within the engine oil.

The engine oil quality sensor is designed to monitor the condition of the engine oil by measuring the amount of soot loading within it. Soot is a byproduct of combustion that can enter the oil, especially in diesel engines, leading to increased wear and decreased lubrication properties. By measuring soot concentration, the sensor provides valuable information about the oil's ability to perform its function effectively.

While water concentration and sludge loading can also affect oil quality, the primary purpose of the oil quality sensor is to detect soot, which directly correlates with the oil's ability to maintain performance under operating conditions. Understanding soot loading helps in determining when the oil needs to be changed to prevent damage and ensure optimal engine performance.