Acceptance variable

I am calculating a value using an iterative algorithm where the value is updated until the change between the current and previous value falls within and acceptance region

The code is below. Any ideas on a better name for the acceptance range as sometimes I think can be misleading

      IF ( EIGVAL_CHANGE <= ACCEPTANCE_RANGE_EIGVAL_CHANGE ) THEN
        EXIT
      ENDIF

Tolerance ?

And don't forget to test for the absolute value of the difference.

sounds ok