In the test of oil pressure tester, the extraction of oil sample is an important work. Different test environment, different process, insulating oil sample collection methods are also different. The container and sampling method used for sampling directly affect whether the actual quality of oil can be reflected.

1. Sampling should be carried out on dry and sunny days. The oil sample for pressure test should be controlled above 0.5kg, and the oil sample for simplified test should be controlled above 1kg. Sample containers are colorless glass bottles with 0.5 kg or 1 kg of wide-mouth sand glass stopper. Two to three vials were collected at a time for analysis and test. Label the sample and pay attention to the oil sample name, source, sampling date, sampler, weather conditions and other information.

2. Before using the sample container, please clean it with gasoline, soapy liquid or other solvent to remove oil, so that it is not alkaline, rinse with water, until the water used flows down the wall of the bottle evenly. Wash it several times with distilled water. The cleaned sample container is dried in an oven at 105 degrees Celsius. After cooling, close the cork. Do not open it before use. After collection, firmly wrap the glass stopper with clean paper and cloth to prevent dirt and moisture from fouling the bottle mouth.

3. Outdoor sampling should be carried out in sunny days or dry weather with low humidity, and the intrusion of garbage such as rain and snow should be strictly prevented during sampling. The oil in the oil storage equipment should normally stand for more than 8h before sampling. If sampling is done in a running transformer, there is no need to stand. Before and after sampling, clean or hairless fine cloth should be used to wipe the area around the sampling port clean. When collecting oil samples from the transformer in operation, discharge about 2kg of accumulated sewage from the bottom of the drain valve or sampling valve at the bottom of the tank, clean the drain port, and then collect oil samples.

4. When collecting the new oil supplemented from the transformer and the oil sample just filtered, please fully stand before collecting the oil sample. From no drain pipe (or throttle) small transformer sampling, can be inserted into the transformer when it does not work with glass tube, extract the bottom of the oil sample, can also replace the sampling using oil change method.

5. When extracting from the tank, open the barrel cover, insert the clean and dry glass tube into the oil, press the tube mouth with your thumb, loosen your thumb, put the oil into the tube, press the tube mouth with your big finger, lift the glass tube, rotate while oil in the tube, clean the sampling tube, circulate 2 times after use. When sampling in batch drums, samples shall be selected based on 5% of the total number of drums, but not less than 2 drums. To use small buckets or whole bottles for sampling, 2% of the total number of barrels (bottles) shall be sampled. When extracting oil samples, the site fire prevention regulations shall be strictly observed.