ISO 5661:1983

Petroleum products — Hydrocarbon liquids — Determination of refractive index

Gives a method for the determination of this quantity of transparent and light-coloured hydrocarbon liquids such as are used in capacitors, transformers, circuit breakers and in cables of the oil-filled type. This method is applicable to liquids having indices in the range 1,33 to 1,7 and at temperatures of 20 to 30 degrees centigrade. It is not applicable, within the accuracy stated of liquids having bubble points so close to the test temperature that a reading cannot be obtained before substantial deterioration takes place.