Yes, they have a 30 day "hassle free" return policy. I have no experience with it, but the fine print reads, to me, like I wouldn't get a full refund.
Their policy for defective machines is 7 days then you must return it to the manufacturer.
Sadly, I have nothing to compare the ground balance to. It was coming up in the 50s I believe. Before this machine I have only used Analog type machines.
I will keep testing with it, and probably contact Nokta for a repair or exchange - if I feel confident in the machine being defective. They seem like a great company that will stand by their product.
Thanks again for replying