变压器油在使用过程中会受环境污染和氧化产生的树脂和沉淀物的影响从而发生劣化，或是在变压器有故障时，均会导致其外状发生改变。利用油的外状对变压器油及变压器的运行状况做出判断分析是一种基本、直观的判断方法。
Transformer oil in the process of use will be affected by environmental pollution and oxidation of resin and sediment, resulting in deterioration, or in the case of transformer failure, will lead to its appearance change. It is a basic and intuitive method to judge and analyze the transformer oil and its operation condition by using the appearance of oil.
用玻璃杯从变压器底部取样阀中取出少量变压器油油样后，对着阳光仔细观察，良好的变压器油应该是清洁而透明的，不得有沉淀、机械杂质、悬浮物质及棉絮状物质。
After taking a small amount of transformer oil sample from the sampling valve at the bottom of the transformer with a glass cup and observing it carefully in front of the sun, a good transformer oil should be clean and transparent, free of precipitation, mechanical impurities, suspended substances and cotton flocculent substances.
一、若油样颜色为棕色或褐色，其酸值和水溶性酸往往接近或超过国际标准注意值，但是，其色谱分析没有一定的规律性。一般情况下，对于颜色较深的变压器油，应加强油的化学监督试验，缩短实验周期，或者可以说，就不适宜再用了。应对变压器油进行再生处理，以防止事故的发生。
1、 If the color of the oil sample is brown or brown, its acid value and water-soluble acid are often close to or exceed the international standard value, but its chromatographic analysis has no certain regularity. In general, for dark transformer oil, chemical supervision test should be strengthened to shorten the test period, or it is not suitable for reuse. The transformer oil should be regenerated to prevent accidents.
二、若油样油色发暗，其简化分析中，酸值和水溶性酸均严重超标。一般情况下，油色发暗，则可能为油的老化现象，变压器内部无故障。
2、 If the color of the oil sample is dark, the acid value and water-soluble acid in the simplified analysis seriously exceed the standard. Generally, if the oil color is dark, it may be the aging phenomenon of the oil, and there is no fault inside the transformer.
三、若油样油色发黑，其简化分析中，闪点往往接近或低于国际标准要求的极限值。色谱分析中，氢气和乙炔组分增高也是一重要特征。一般情况下，油色发黑可判断为变压器内部可能存在放电现象或是放电兼过热现象，变压器油因变压器固体介质的炭化而变黑，放电严重时会造成设备烧毁，甚至发生爆炸事故。闪点过低也会导致变压器发生火灾，甚至爆炸。对于油色发黑，且闪点过低的油应特别引起注意。
3、 If the oil sample turns black, the flash point in the simplified analysis is often close to or lower than the limit value required by the international standard. In chromatographic analysis, the increase of hydrogen and acetylene components is also an important feature. In general, the blackening of oil can be judged as the discharge phenomenon or the discharge and overheating phenomenon inside the transformer. The transformer oil turns black due to the carbonization of the solid medium of the transformer. When the discharge is serious, the equipment will be burned, and even the explosion accident will occur. If the flash point is too low, it will lead to fire or even explosion. Special attention should be paid to the oil with black color and low flash point.
四、若油样浑浊发白，其简化分析中，击穿电压的降低和氢气含量的增高是油样浑浊发白的两个重要特征。一般情况下，如果油样浑浊发白，则很可能是油中含有水分造成的，可大致诊断为变压器油内部进水受潮。这里有一个简易方法来大概得知配电变压器油击穿电压值合格与否，而无需用油的介电强度测定仪来判断。取一只无色透明经过烘干的平底玻璃杯，从变压器底部取样阀中取出少量的油样，使之在玻璃杯中形成７ｃｍ高的油柱，在光线充足处，将杯底紧贴报纸，从上望下透过油柱，如能看清６号字，则该油样的击穿电压应在２５ｋＶ以上。而在１０ｋＶ配电变压器运行中，绝缘油的击穿电压要求不低于２５ｋＶ。
4、 If the oil sample is cloudy and white, the reduction of breakdown voltage and the increase of hydrogen content are two important characteristics in the simplified analysis. In general, if the oil sample is turbid and white, it is likely to be caused by water in the oil, which can be roughly diagnosed as moisture in the transformer oil. There is a simple way to know whether the breakdown voltage of the oil in the distribution transformer is qualified or not without using the dielectric strength tester of the oil. Take a colorless transparent dried flat bottom glass, take a small amount of oil sample from the sampling valve at the bottom of the transformer to form a 7cm high oil column in the glass. In the place with sufficient light, place the bottom of the glass close to the newspaper and look down through the oil column. If you can see No. 6, the breakdown voltage of the oil sample should be above 25kV. In the operation of 10kV distribution transformer, the breakdown voltage of insulating oil is required to be no less than 25kV.
以上所述可以作为对变压器油油质和变压器可能出现的故障做出的初步判断。同时可根据其异常情况的不同，明确需要进行的油化学监督试验项目，以对设备故障及早做出进一步准确的诊断。
The above can be used as a preliminary judgment of transformer oil quality and transformer faults. At the same time, according to the different abnormal conditions, the oil chemistry supervision test items that need to be carried out can be made clear, so as to make further accurate diagnosis of equipment failure as soon as possible.
