the linearity error to be adjusted in the opposite of direction of the error? is it true

 

You didn't say linearity of what.

For Bourdon tube pressure gauges and old style controllers like a Foxboro 43AP you adjust

Zero then Full scale (span)
Set the input to give about 50% full scale then adjust linearity to show about 5 x the error.

Do zero and full scale again
check linearity and you will find it quite close.

Try it!
Roy