I had a final inspection today and the city inspector was testing the arc-fault circuits. One of them was working properly while the other one was not tripping with his tester, yet it tripped with the test button. I was not present at the time so naturally he failed me. I arrived at the job 2 hours later and tested it with my tester (Ideal SureTest #61-056) and it worked fine. The braker is a SquareD homeline but I installed it in December and it is supposed to be a post-recall breaker - the test button is green which my supplier says is post recall. Is it possible that my tester is substandard to the inspectors tester? How does an arc-fault tester work exactly? Thanks in advance for any thought on this.