Natan

Processing usually includes pre filtration to remove solids, heating to reduce viscosity, vacuum dehydration to remove dissolved and free water, vacuum degassing to remove air and fault gases, and fine filtration to improve cleanliness. Some processes include adsorption or clay treatment to reduce acidity and polar compounds, and inhibitor adjustment if required. Oil is then cooled, sampled, tested, and transferred using sealed lines to avoid re contamination. Final acceptance is based on standards for BDV, moisture, acidity, interfacial tension, and resistivity.

Transformer systems use mineral oil, natural ester oil, synthetic ester oil, or silicone oil. Selection depends on voltage rating, cooling requirements, fire safety, environmental impact, and cost. Mineral oil remains widely used due to proven performance and affordability, while esters are chosen for fire safety and biodegradability.

Quantification is done by laboratory analysis that reports PCB concentration as ppm or mg per kg. The lab method identifies either total PCBs or specific mixtures and applies calibration curves to convert detector response into numeric concentration. Multiple runs and quality checks ensure accuracy. The reported concentration is compared against regulatory thresholds that classify oil as non PCB, low level contaminated, or PCB containing. This classification directly affects storage, transport requirements, and disposal options during maintenance or retirement.