Units of Measurement Standards
When should I use meters and when should I use feet?
The primary units used to measure distance are the meter and the U.S. Survey foot. UTM
distances are usually expressed in meters. State Plane distances are usually expressed in
U.S. Survey Feet, and tenths and hundredths of feet, when using NAD27 datum; and,
meters when using NAD83.
What is the difference between a foot and a surveyor's foot?
The definition of the yard resulted in the imperial foot being 0.3048 meters exactly.
However, in the USA, in 1866 the meter was declared to be 39.37 inches. This made the
US foot to be 0.3048006096---- meter (approx.). Not a lot of difference? It was to
scientists and engineers, especially as measuring instruments became more and more
accurate. It was not until the 1950's that agreement was reached on that, when the
imperial definition was adopted by the USA.
In the meantime, most of the USA had been surveyed using the 1866 definition that
became identified as the US Survey Foot. Metrication of the survey undertaken towards
the end of the 1900's used, for conversion purposes, the fact that 39.37 US(survey)feet =
12 meters (exactly).