Soot level – a diesel engine lube oil condemning limit

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Courtesy of Spectro Scientific

While there is widespread disagreement on used-diesel oil condemning limits, it is well known that excessive soot in the lube oil causes abnormal valve and injection-train wear.  It can also increase exhaust emissions and clog filters.  Typically, the suggested limit for soot is in the neighborhood of 3% but can go much higher. 

With the new ASTM Method D7686, truck, bus, ship, locomotive, and off-highway equipment fleet operators, power generation plants, as well as used oil labs and engine test facilities, have an easy, on-site analysis method that accurately measures soot percent levels in under 30 seconds – without sample preparation, dilution, or messy transmission cells to clean. This ASTM test method for field-based condition monitoring of soot in in-service lubricants uses the InfraCal Soot Meter which is a filter-based infrared analyzer. The InfraCal Soot Meter is factory calibrated for measuring levels up to 12%-15% and provides a fast, simple field spectroscopic check for helping to diagnose the operational condition of the diesel engine. 

The InfraCal Soot Meter is portable, weighs less than 5 pounds, and is roughly a 6 inch cube in size. Its rugged construction which is sealed against accidental spills, plus no moving parts, makes it the perfect instrument for field-based operation and easily operated by non-technical personnel. However, many are used in labs to free-up their FTIR spectrometer for more complex analyses. It is also relatively low-cost when compared to more sophisticated and complex analytical instrumentation such as FTIR or TGA. Analyzing a used oil sample with the InfraCal Soot Meter takes only a couple of quick steps – apply a sample to the built-in ATR crystal, push the run button, and the percent soot is displayed in less than 30 seconds. Then simply wipe the crystal clean with a soft cloth and apply the next sample. 

Field-based soot analysis supplements preventative maintenance programs with rapid screening for added assurance of equipment or vehicle performance while in service. In addition, field screening can provide cost savings by extending drain periods and reducing expensive sample disposal while helping to avoid potentially catastrophic engine failure.

For individuals involved with used oil testing or maintaining diesel engine reliability and performance, the InfraCal Soot Meter provides an easy, accurate ASTM method for determining the soot levels in diesel lube oil.  There's not an easier or reliable and dependable workhorse of an instrument!

Customer comments

  1. By Muhammad Farooq Alam on

    very good addition in monitoring regime