Compliance with following International Standards:
ASTM D2440, IP 280
Introduction:
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.
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.
2 nos. test vessel / tube made of borosilicate glass provided with a B -24 cone and
having the following
Dimensions: Tube
Overall Length : 210 /- 2 mm
External diameter : 26 /- 0.5 mm
Wall thickness : 1.4 /- 0.2 mm
Height of head : 28 /- 2 mm
Oxygen inlet tube Dimensions:
External dia : 5.0 /- 0.4mm
Wall thickness : 0.8 /- 0.1 mm
The test tube is fitted with a Drechsel head to which is attached the inlet tube which will extended within /- 2 - 3 mm of the bottom and its end ground at an angle of 60 deg to the horizontal axis as per fig 1 of IS :335 : 1993
Brief Construction Details
The complete unit comprises of following main parts and accessories
One Thermostatic block of following features:
It is made of wrought aluminium block provided with 2holes to accommodate 2 test vessels / tubes, provided with a digital PID controller, capable of maintaining the oil temperature at 100.0 /- 0.5 deg C. 2nos.
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 approx 20 mm external diameter and 50 mm in length.
Rotameters of following features:
These are rota meter type flow meters with the capacity to measure the flow rate of oxygen in the range 1 /- 0.1 litre / hour.