The characteristics of oil which are used for the lubrication of bearings and transmission can tell us a lot about the processes which occur inside the machine.
The laboratory at RWlab uses some very simple methods for oil analysis. These results are used for confirming those achieved by the measurement and analysis of the spectrum of vibrations. These methods are:
- Patch test
- Transpirency test
- Crackle test
- Viscosity Test
All the above methods are constructed in a way so that they can be conducted on-site and without greater preparation. The results of the tests are available only a few minutes after sampling the oil of the machine..
The Oil Patch Test
The Oil Patch Test provides a qualitative measure which is used for confirming the dimensions and types of metal impurities in the oil.
The procedure of the method is very simple and consists of:
- Diluting the oil sample so as to decrease viscosity
- A patch membrane of the diluted sample is placed over a micron filter with the help of a vacuum pump
- The filter is placed under a microscope where it is photographed and the photographs are analysed and documented
The Oil Patch Test enables us to discover:
- Metal particulars which are a result of damaged bearings or gears.
- Polymer contamination due to damaged seals.
- General contamination resulting from carbon dust, cement; depending on the environment the machine is found in.
- Organic contamination (algae in oil) etc.
A metal splinter (10μm) as a result of a damaged bearing rolling surface
By combing the results of the vibration spectrum analysis and the oil patch test, we can achieve very reliable results and see what damage was caused to the bearings and gears. We can also discern specific problems, such as the extent of contamination of damaged seals or the development of algae in the oil.