However, the number 0.133224 is not exact - there are many more decimals that could be added provided someone had an experimental system that was sufficiently well-designed to measure very minute changes in pressure. For example, the true value might be 0.13322425436432, but with the resolution of our current measurement systems, the above conversion factor (0.133224) is what we're stuck with.

Fine. We have a limited resolution for the accuracy of the conversion of mmHg to kPa. How does this affect my life?

The answer is that the conversion factor with the smallest number of significant figures determines the overall accuracy of any calculation (the above conversion factor has 6 significant figures). That is to say, if I multiply the above number times Pi (which has >> 30 significant figures), the resultant answer must be limited to 6 significant figures. If we allow any more than 6, we are fooling ourselves into believing our result is more accurate than it actually is.

Most conversion software packages do not differentiate between conversion factors, and thus often give erroneous results. OmniCon, however, is different. OmniCon analyzes each conversion factor involved in a calculation, and limits the answer that you see on the screen so that it represents the smallest number of significant figures in the calculation. Thus, OmniCon gives accurate results every time, and prevent you from worrying about the actual accuracy of your calculation.

OmniCon is the only software available that has this important function!

On OmniCon's main window, you will see a status bar at the bottom of the window:

Click on the 'Next Page' link below to continue the explanation of Significant Figures.

Significant Figures Home | Next Page