Help, I need to buy a torque wrench

http://www.sears.com/craftsman-micr...p-00931425000P?prdNo=1&blockNo=1&blockType=G1

I have this torque wrench. I just finished testing the calibration of the wrench. I was using 35 lb and a 25 lb plate weights from a weight set. I was coming up with about 9-10% off to the heavy side assuming the weights are accurate. Set at 90lbs, it would give 98-99lbs. I just tested mine because I am changing out a head gasket and wondered if it might be on the light side. Torque is not a true accurate measurement of tension in a bolt, but I am still considering buying a new torque wrench with more accuracy. After reading all the reviews, it looks like it is a matter of time before it breaks.