http://assets.fluke.com/datasheets/2153ExtSpecs.pdf
I just had a look at the '189's spec's on their site. They say it's good for .25% + 20 counts measuring DC, higher than that if AC. But, they also state that's only if the meter has been cal'd in the last year. Short answer from me anyways...it should be able to measure those currents without a problem...
Not sure about the other problems. I didn't see anything in the errata that caught my eye. I'd be inclined to think that your problem lie elsewhere, the power grid, something else in the room, static charge, something... I don't know enough about what you've got going on.
(Ya know, using a power switch doesn't draw much currentI kid...I kid...)



I kid...I kid...)


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