Water Content in Lubricating Oil

If you have a pure sample of oil, for instance of the water is getting into the oil through use, you can weigh equal volumes of pure oil, pure water and the oil with water mix. and calculate their densities. Oil is less dense than water any increase in density of the oil is directly proportional to the amount of water in the oil. Of course if the water gets in the oil through use then other contaminates could be in the oil as well so that will throw off the calculation. You may also be able to centrifuge the sample and separate the water and oil and get relative volume measurement.

you may take a small sample of oil in a spoon and hit with a lighter. ONe way to determine is by colour. If there is water then colour of oil will turn milky. If small bubbles are formed, water content is small or negligible and if larger bubbles are formed water content may be significant. And if there is cracking sound too, water content is very high and need to be replaced quickly.

john, UK

THis is a common problem in the used oil recycling business. There are several ways to check water content in used oil that is very inexpensive and accurate. Call a local used oil dealer and I am sure they will be glad to help you.

If you cannot find someone to help, post back here with some kind of contact information and I will be glad to help you.

good luck

If you take a spot sample, it must be representative of the total volume. Taking a sample once a day or once a week will not tell you very much. It is also not scientific. If you are convinced the only way is to take spot samples, then take as many samples as possible- The more frequent the samples , the more likely you are to detect water in the oil. If you can take one hundred samples a day, it may begin to give you an indication of what is flowing through the total oil volume at different times of the day.

Alternatively install an online water in oil monitor that will act as a continuous sample.

I have worked in pulp and paper manufacturing for 42 years as a millwright and one of the biggest problems was water contamination in all the oil systems, The oil product i found was from Mobile Oil. The unit measured water in oil using a carbide powder which turned water to a gas when mixed with oil and kerosine/diesel to dilute sample, when shaken in the supplied container gas created caused an increased pressure in container pushed liquid up a site tube and reading was taken and checked on a table giving the % of water contanination. this is brief discription. the company developed this for quick checks on fuel tanks on large ships to keep from flame outs in boilers. Check with Exxon/Mobile as this was available several years ago and was a complete kit with 30 packets for one for each test field test. to me a very accurate field test. i don't know if kits are still available.

I know this is going to sound like BS, but the lab use a hot plate and observe the crackle. To get percentage is a titration like process using known concentrations and comparing the crackle.