Example of use: To convert millibars to psi, find
the 1 under the millibar column. The 1 marks the row that contains multipliers
to convert millibars to other units. Follow the row to the psi column.
The multiplier is 0.014504. Thus you would mulitiply the millibar
value by 0.014504 to convert it to psi. Note that factors related
to head of water are derived from water at a temperature of 4 degrees
C ( 39.2 degrees F).