Hi guys, just got my self a brand new tester to have a play with and get used to testing. Just a few things i wanted to know 1- when its brannew does it need calibrating? And 2- in my house got a 3036 board when i do a loop test it gives me a reading of say 0.25 if i do it agian its 0.37 and so on goin up, whys that? 3- is got ATT on it do i turn that off when testing 3036 boards? Cheers guys