Setting up "error factor" (range calculation) and "conversion" calculation
I am building a searchable "catalog" of items based off physical attributes and descriptions. Two of the attrubutes, length and width, are entered into the database in millimeters when the item is added. I would like for the users to have the ability to use inches, or feet in addition to millimeters when they search for an item. Also, to have the ability to enter an "error factor" when adding their measurements to the search layout.
ie: I have a searchable catalog of cell phones, users can search for phones by any or all of the following attributes: manufacturer, category, os, color, length, width, keywords (nickname). Say they dont know the exact dimensions of the phone in millimeters, all they have is a ruler with inches that isnt very accurate, so they enter 4 and click a radio button or select from a dropdown list for a measurement in "inches" and an error factor of +/- .25. All items in the catalog (after their measurement is converted to millimeters) that have a value between 3.75 and 4.25 inches would be displayed on a search summary page.
I have all they layouts completed and about 1400 items in the catalog already, the problem is that users have to know the exact dimensions of an item in millimeters to return results on the search summary layout.
Thanks in advance for any assistance!!