1. On-line sampling and testing: It is mainly used to connect the sampling port and testing equipment with a catheter for sampling and testing. This kind of sampling detection (with little external influence and high detection accuracy) is mainly to pay attention to the selection of sampling ports. There may be differences in the degree of contamination of the oil at different locations in the system, so the correct sampling port should be selected for sampling and testing.
2. Offline sampling and testing: Take the oil in a container at the sampling port and send it to the laboratory for testing. This sampling method is more commonly used (simple and easy to operate), but there are also large influencing factors, which are likely to cause secondary pollution (cleanliness of the container, sampling environment, operator's operation, etc.).
1. The cleanliness of the sampling container should conform to the ISO 3722 inspection standard (the number of particle pollutants larger than 6μm(c) in each milliliter sampling volume should be less than 20);
2. The sampling container should have a container cover. When sampling oil on the construction site or in the production workshop and other environments with high dust content in the air, the wind direction (the operator’s back to the wind direction) and the sampling point (there is The selection of objects to be shielded should be controlled. After sampling, close the lid in time and keep your hands away from the inside of the lid to prevent pollutants from the environment and hands from falling into the container after sampling and affecting the detection results of the oil;
3. The volume of the sampling container should be sufficient to ensure that the oil can provide multiple tests.
Precautions:
1. On-line sampling detection and off-line sampling detection, when sampling, the oil in the sampling pipeline should be discharged for a period of time before sampling to prevent the contamination of the sampling port from affecting the detection results.
2. The sampled oil should be defoamed and dewatered to prevent bubbles and moisture from affecting the test results.
3. The oil should be tested for several times and the average value should be taken to evaluate the oil pollution level.