Torque Wrenches

[metro1]

How does everyone maintain the accuracy of their torque wrench? I've had mine for quite a few years and have no idea how accurate it is. From what I've seen on the net is costs more to get one calibrated than a new one. I saw how some people hang a weight on the handle and using a math formula do it that way but that was debatable if it was really accurate. I need to install new head gaskets and need to be sure for proper torque. I guess I could buy a new one but that might not be correct either.