I got a cheapo multimeter off fleaBay. When I power it up to check an atty, the digital display shows a 1. The number doesn't change if I touch the prongs together. Does this mean I should be subrtracting a 1 from my overall reading? All my standard atties measure out at 3.5 and my LR's at 2.4 - 2.5. Does this mean the standards are really 2.5 and the LR's 1.4 - 1.5?