Welcome to Geekhack.
Would you mind RipOmeter (http://geekhack.org/showwiki.php?title=Island:6189)ing your Omron sometime? Then I can give better advice.
My, the wiki loading time was extremely painful. At this rate I will not be able to answer many noob questions.Show Image(http://geekhack.org/attachment.php?attachmentid=24476&d=1313514758)