Information of Units

Information of Units   (12/24/2008, 1:17 AM)

Hi,
I am not getting any information on some of the units. Please provide me help for the following units.

1. "in of H2O Vacuum" and "inches of H2O" are same units?
2. "integral index-seconds" is SI unit?
3. What is "% slope error" unit? Is it SI unit?