The instrument consists of a rotating test ring against which a fixed test ball is pressed with the required force. A fuel bath containing the fuel under test is placed on – movable stage under the test ring. The temperature is controlled and the air is conditioned. The fuel under test is conditioned by maintaining the fuel temperature at 25°C with 10% relative humidity and is passed through the test area which is enclosed. After conditioning of the fuel, a test ball of 12.7 mm diameter is pressed against the outer surface of the test ring. The lower part of the test ring is immersed in the test fuel bath. The test ball is pressed with a force of 10 N against the test ring. The test ring is made to rotate at 240 RPM for a period of 30 minutes after which the test stops. The wear scar on the test ball is studied and the scar diameters of the wear scar (major and minor axis) are measured. Data Acquisition Test parameters such as speed, test duration, fuel temperature, air temperature and humidity are acquired, displayed and recorded. The acquired data can be viewed in graphs. The data acquisition system provides the users with the facility to superimpose up to four test graphs for comparative viewing.