ASTM D2440, IP 335 ASTM D943
This test method determines the resistance of mineral transformer oils to oxidation under prescribed accelerated aging conditions. Oxidation stability is measured by the propensity of oils to form sludge and acid products during oxidation.
Significance & Use
A test specimen of mineral transformer oil is oxidized at bath temperature of 110°C/95°C, in the presence of a copper catalyst coil, by bubbling oxygen through duplicate test specimens for 72 and 164 h, respectively. The oil is evaluated at the end of each aging period by measuring the amount of sludge and acid formed. The test specimen is diluted with n heptane and the solution filtered to remove the sludge. The sludge is then dried and weighed.
Brief Construction Details
The complete unit comprises of following main parts and accessories
Oil Receptacle and Head
Provided with B 24 cone having the following dimensions:
Oxygen inlet tube (Delivery Tube) Dimensions
The test tube is fitted with a Drechsel head to which is attached the inlet tube which will extended within 2.5± 0.5 mm mm of the bottom and its end ground at an angle of 30° to the horizontal axis.
Nos. Metallic Copper Catalyst of following dimension
Copper catalysts consist of a wire of non annealed commercial electrolytic copper of diameter between 1.00 and 1.02 mm. And wire shall have a length of 305 ± 1.0 mm rolled into a spiral of approximately 20 mm external diameter and 50 mm in length.
4 nos. rotameters (flowmeters) of following features
These are rotameter type flowmeters with the capacity to measure the flow rate of oxygen in the range (1± 0.1) litre / hour in case of ASTM D2440 test method or (3± 0.1) litre / hour in case of ASTM D943 test method.
Following accessories will be the part of standard supply