I'm taking a CWI exam prep class at a local junior college.  Last night we started preparing for Part B of the exam by considering the undercut adjacent to a plastic butt weld replica.  The scale on the V-WAC gauge in my kit was divided into increments of 64ths of an inch.  Using that gage, the depth of the undercut measured more than half a 64th greater than 1/32", in other words the total depth was about .039".  The Part B code says the maximum acceptable undercut adjacent to a butt weld parallel to the axis of the primary stress is 1/32".  An AWS sample test question asks if the undercut is acceptable.  .039" is greater than 1/32", so I say the weld isn't acceptable, but the AWS answer key for the test says that the weld is acceptable.  I don't get it.  My instructor suggested that the measurement wasn't "enough" over the limit to be considered over the limit, and he cautioned against making the measurement process harder than it needs to be.  That doesn't give me a very good feeling.  I can rationalize either answer, that the weld was or wasn't acceptable, but only one opinion will be counted right on the day of the exam.  Can someone direct me to an AWS document that says in black and white that a measurement must be at least a full unit on a gage scale above the maximum permissible limit to be considered as exceeding the limit.