DT100DL  Lubricant Dispersancy Tester​


Measurement of the Merit of Dispersancy of In-Service Engine Oils with Blotter Spot Method


ASTM D7899



The requirement for on-line machinery and oil condition monitoring is becoming evermore apparent as maintenance costs increase and production capacity and equipment performance are maximized.


One of the primary functions of a lubricant is to preserve the cleanliness of a combustion engine's mechanical parts. The cleanliness of the mechanical parts is facilitated by "detergency" and "dispersancy" (DD) additives in the engine oil..


The dispersancy is the property that allows the oil to suspend and carry away "pollutants" of diverse sources such as soot from combustion, metallic particles from wear, corrosion of mechanical parts, and insoluble products resulting from the ageing of the oil, etc. Dispersant additives in oil prevent agglomeration and sludge formation by dispersing contaminants. With proper formulated oil, the soot will remain homogeneously suspended up to high concentration levels. When soot load reaches a critical limit for current condition of the oil, a sudden loss of dispersancy leads to rapid agglomeration and deposition of soot onto machine surfaces. Contaminants like water and/or glycol can quickly knock out dispersancy performance without an increase in soot load. Diesel engine condition monitoring requires increased focus upon measuring both soot concentration and dispersancy performance. Unlike measuring soot concentration where numerous options exist, measuring soot content and dispersancy performance is a real challenge to the oil analyst.


The DT100DL operates according to ASTM D7899. The instrument simultaneously measures soot and dispersancy. The results reported are combining soot content and dispersancy performance.



A dedicated method is under approval process. This test method could be an alternative to very long and expensive test which is the engine test like DV4TD - CEC-L-93-04 where the pistons and rings are rated.


Phase 1 - a drop of oil is injected on a filter paper


Phase 2 - the drop spreads on the paper


Phase 3 - the oil with contained particles penetrate into the filter paper. The oil that is properly dispersing soot and other insolubles produces an evenly graduated spot. Dispersion characteristics of the oil are judged by how far oil drop spreads, how big the central sooty area is and how homogeneous the opacity of the spot is. The opacity of the spot will provide information on the oil contamination level. Though this method has proven effective, individual subjectivity in readings oil spots affects the reliability of results. To help oil analysts taking most advantage of this valuable traditional technique the company AD systems in cooperation with a lab dedicated in Oil Conditioning Monitoring (OCM) has developped a modern automatic instrument DT 100 offering significant increase in accuracy and repeatability of measurements. This new technique removes all the arbitrary aspect of the manual method.



  • Oil Conditioning Monitoring (OCM)
  • Oil testing labs
  • Engine test labs
  • Fleet maintenance shops
  • Constructions or Mining sites
  • On-board ship
  • Lubricating Oils plants
  • Synthetic lubricants plants



Unique and simple instrument to measure dispersancy

Complete OCM program with unique information on oil dispersancy


Dispersancy measurement and soot content quantification

Tool to make justified pro-active actions and maintenance planning decisions


Removes all arbitrary aspects of manual method

Evaluation of oil formulationPerformance of DD additives


Ideal for trend analysis in OCM programs and diagnosis on diesel engines

Lubricants performance at engine operation conditions

Lubricants compatibility evaluation



The DT100 takes a spot image with a built-in digital camera. In seconds, the software scans and analyzes all the different areas of the oil spot and automatically calculates the quantitative quality parameters of a motor oil in service. The DT100 has been designed to satisfy needs of OCM laboratories. It is an easy-to-use and robust analyzer equipped with enhanced quality and communication features. The spot images can be stored on USB storage devices and sent to local networks (LIMS) with an Ethernet interface. Versatile communication protocol is configurable for the specific requirements of each laboratory. The DT100 provides fully traceable electronic data storage eliminating the need for paper archiving. A laboratory technician can perform on-site calibration in minutes using a standard calibration tool supplied with the instrument. The DT100 complies with modern QA/QS laboratory practices.



The index of contamination (IC) is the concentration of insoluble soot loading in a diesel engine oil charge and is expressed as weight percent. Such contaminants cause a rise in the viscosity of system oil and may result in the formulation of sludge, which can lead to excessive component wear. The merit of dispersancy (MD) indicates the ability of the lubricant in a diesel engine to carry combustion contaminants in suspension. It is expressed as a number from zero to 100. Providing an adequate dispersancy level is maintained, the amount of insoluble soot that can be tolerated increases and the diagnostician can make informed recommendations to the vessel's engineer about the treatment of the remaining oil charge. The lubricant's inability to maintain the contaminants in suspension may lead to deposits accumulating in the bottom of the crankcase and cause problems with filtration and/or purification equipment.



MD = 0 = poor dispersion: the insolubles are all concentrated in the centre of the oil spot in the test; the residues are flocculated.MD = 100 = excellent dispersion: the distribution of the insoluble on the filter paper is homogeneous.The demerit points (DP) figure reflects the overall condition of the oil, as it is a combination of the IC and the MD derived from the calculation DP = (100 - MD) x IC. A low DP (0 or close to 0) indicates slight contamination and excellent dispersancy. A high DP (approaching 100 or more) indicates heavy contamination and/or a poor dispersancy



The DT 100 has been designed to satisfy needs of OCM labs. It is an easy to use and robust analyser equipped with enhanced quality and communication features. Connection to LIMS can be done with Ethernet interface. The DT 100 software is able to manage local network connection with user login and password. Data format and storage options are configurable for specific requirements of each laboratory. The test data can be simply downloaded on USB memory stick, saved in local network or printed. When connected to a printer, the results data are automatically printed out after each measure.


Spot image storage

Storage of filter sheets with spots doesn't make sense because the oil spot is changing and degrading over time. It is important to "freeze" the spot at the moment when contamination and dispersancy measurements were taken. The DT 100 tester is offering electronic data storage features eliminating paper reports archiving. The images can be stored on USB storage device or be sent to local network. The DT 100 can store spot bitmap images taken with backlighting (DT 100) or with front lighting (DT 100DL). The DT 100DL (Dual Light) is equipped with additional light source, color camera and specific software. This DT 100DL configuration offers the possibility of taking and recording the color picture of the spot in front lighting as it is seen by human eyes. In addition to quantitative parameters of the spot




DT100DL Brochure



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