High Temperature Knock Testing: An Account of Experiments on the Precision of the U.S. Army Air Force Specification Available to Purchase

WHEN the U.S. Army Air Force adopted its specification for anti‐knock petrol (Y‐3557‐B) involving the use of high jacket temperatures, relatively little information was available concerning the precision of the test, or the agreement to be expected among different laboratories. A short co‐operative programme was arranged, therefore, among several laboratories interested in the subject, to determine for the types of fuel likely to be employed in meeting the Army specification the agreement to bo expected from different laboratories using the specified technique and a brief study of some of the variables likely to be met.