HK-0308  Air release value apparatus conforms to the ASTM D3427 standard  Test Method for Air Release Properties of Petroleum Oils. It is used to test the ability of turbine, hydraulic, and gear oils to separate entrained air. This apparatus measures the time for the entrained air content to fall to the relatively low value of 0.2% volume under a standardized set of test conditions and hence permits the comparison of the ability of oils to separate entrained air under conditions where a separation time is available. The significance of this test method has not been fully established. However, entrained air can cause sponginess and lack of sensitivity of the control of turbine and hydraulic systems. This test may not be suitable for ranking oils in applications where residence times are short and gas contents are high