I would first measure the torque myself to see if it needs calibration. A friend and I did with our various torque wrenches and found them all good.
Make a simple arrangement of a bar with a bolt on one end and some known weights on the other hanging by a wire. Measure the distance between bolt center and weight attach wire. Then set a few different torque settings and torque on the bolt until the wrench clicks. Compare with your calculation of the known torque. I think we did three settings; low, mid, and high. All came within a few percent of known torque so we figured we were good to go.
Even if your wrench needs adjustment you can find instructions on how to do so online.