How is testing of transformer oil performed in laboratories and field kits?

Laboratory testing uses controlled instruments and standard methods to measure moisture, acidity, interfacial tension, dissipation factor, resistivity, and dissolved gases. DGA is typically done by gas chromatography after extracting gases from the oil. Field kits focus on fast screening: portable BDV testers, moisture meters, and sometimes quick checks for acidity or dielectric loss. Field results support immediate decisions after maintenance or events, while lab results provide higher accuracy, broader parameters, and trending data used for long term condition assessment and asset management.