Obtaining an Oil Sample

Obtaining an Oil Sample

Obtaining fluid samples is relatively simple, regardless of the application. Sampling methods may vary according to the type of equipment from which the sample is taken. Mobile vehicles typically require a vacuum pump while common industrial applications may give direct access through a sample valve or system reservoir. Some industrial equipment may require a vacuum pump.

To ensure accurate fluid analysis and reporting, appropriate procedures must be observed. All kits and materials necessary for obtaining an oil sample are outlined on pages 14 and 15 of the Oil Analyzers User Guide.

Vacuum PumpSampling with a Vacuum Pump

A vacuum pump is used to take samples from a dip stick or non-pressurized system.

To use a vacuum pump, securely attach a sample bottle to the pump. Attach a clean tube to the top of the pump and tighten the lock ring. Place the free end of the tube into the dipstick retaining tube or oil fill port, making sure not to allow contact between tubing and bottom of reservoir. Pump the plunger until oil flow is consistent and then pump only as needed to maintain consistent flow. The sample bottle should be filled about ¾ full or to its shoulder. Remove the sample bottle from the vacuum pump and tighten the lid securely.

Sampling through a Sample Valve

Some industrial applications have a sampling port through which a sample can be obtained. This sampling method requires the equipment be in operation. Open the sampling valve and allow a small amount of oil to flush contaminants from the valve. Place the sampling bottle under the valve and obtain the sample. The sample bottle should be filled about ¾ full or to its shoulder. Ensure the sample valve is securely closed once the sampling process is complete.

Sampling from a System Reservoir

If collecting a sample through a sample valve is not possible, the equipment's system reservoir can be used. The oil must be drained from the plug for a few moments before the sample is taken so contaminants that have settled around the drain are flushed out. Once the drain has been flushed, place the sample bottle in the oil stream and collect the sample. Using the reservoir drain plug is the least desirable method for obtaining an oil sample because the bottom of the reservoir contains elevated amounts of contaminants. It should be used only when the other options are unavailable.

Mobile Sampling Locations

Appropriate sampling locations for automobiles, light, heavy-duty and over-the-road trucks include the oil dipstick tube, the reservoir drain plug or petcock valve if one has been installed.

Industrial Sampling LocationIndustrial Sampling Locations

Common sampling locations include the oil reservoir, oil filter, sampling port and filtration mount. If excess wear is detected in industrial applications, samples can be taken immediately before or after particular components, such as pumps or valves, to help isolate which component is producing excess wear elements.

About Us

Oil Analyzers INC. is a fully equipped oil analysis laboratory staffed by highly trained analysts. Oil Analyzers INC. offers a complete line of oil analysis services, including engine oil analysis, drivetrain oil analysis and industrial lubricant analysis.


Oil Analyzers INC.
1101 Susquehanna Ave.
Superior, WI 54880
Customer Service:
(877) 458-3315