TPI

Teachers Pay Initiative

TPI

Tracks Per Inch

TPI

See Tax and Price Index.
Found on http://www.encyclo.co.uk/local/20140

TPI

Tracks Per Inch - this is one way of specifying the amount of data you can store on your floppy discs, e.g. 800Kb 3½' discs (DD) are 135tpi
Found on http://www.archivemag.co.uk/

TPI

Tuned Port Injection
Found on http://www3.sympatico.ca/dhaughey/j1930.htm

TPI

Tap Position Indicator for transformers.
Found on http://www.youngco.com/young2.asp?ID=4&Type=3
No exact match found