> all tape measures must be the exact same length. Tape measures are useful even if they're not the same length. Higher-end engineering tapes acknowledge that

> all tape measures must be the exact same length. Tape measures are useful even if they're not the same length. Higher-end engineering tapes acknowledge that length isn't constant, and provide temperature coefficients, ranges of accuracy, and tensioning guidelines. You can spend a lot of money on a tape measure which is more exact under more conditions. Most people don't need this.