Health assessment of HV transformers is a vital part towards reliable operation for any thermal power plant. The liquid dielectric media inside a transformer carries all information related to healthiness or fault symptoms generated within the system. NTPC-NETRA has established its transformer oil testing laboratory, equipped with sophisticated equipment’s to carry out relevant diagnostic tests that are extremely helpful to adjudge functional health of an energized transformer. Transformer oil testing laboratory carries out important tests like Dissolved gas analysis (DGA), Power dissipation factor (Tan δ), Specific resistance, Break down voltage (BDV), in addition to routine tests (viz., Moisture content, acidity, colour of oil, Flash Point, IFT, Density, Viscosity etc.) as per ASTM / IEC standards This NABL accredited laboratory of NTPC-NETRA has total facility of test requirement for transformer oil as per IS-1866. Specialized tests like, Degree of polymerization of kraft paper, Furfural content in transformer oil, PNA evaluation for base oil composition, etc. have been developed and such services are extended to our external customers as well.