| OELCHECK test instrument: | Microscope: Keyence VHX-X1F Camera: VHX-7020 Software: Keyence Digital Microscope |
| Sample quantity: | 50 ml |
| Unit: | Number of particles |
| Test result: | Cleanliness class in accordance with ISO 4406 Number of particles >2; >5; >10; >15; >25; >50; >100; >150; >250; >500 µm Representative photo of the test membrane Microscopic images of the test membrane |
| Analysis for: | All hydraulic and lubricating fluids, preferably aqueous and murky media (multiphase fluids) |
| Brief description: | The homogenised sample is filtered through a filter membrane with a pore width of 1.2 µm. The membrane is rinsed with solvent and dried, then secured and focused on a motorized cross-slide stage. A representative surface of the filter membrane is microscopically "scanned" in incidental light mode. All particles appearing darker in the grey scale of the membrane are photographed with a high-resolution CMOS sensor, measured using image analysis software and categorised based on their furthest expansion. Representative images of the test membrane are captured at 200x magnification. |
| Statement: | The microscopic particle count makes it possible to calculate cleanliness classes for lubricating greases which cannot be subjected to the classic liquid particle count (optical principle) due to issues such as murkiness. Conclusions may also be drawn on the quality of characteristic particles included e.g. fibres or reflecting particles. Even very dark and/or heavily contaminated fluids can be investigated in a targeted way with corresponding solvents on membranes with deviating pore widths. |
| Underlying test standard: | ISO 4407 |
