You could only check your torque wrench against another that you know to be within spec. Basically a torque wrench has to cost quite a bit of money to be any good. Then they get dropped and messed up. Also, you don't want to use one too big for the job as the bigger they are the more they deviate.
The best value in inexpensive torque wrench is the ones that bend with the arrow. The clicking ones are generally more inaccurate unless $50 and over. IME
