Torque wrench is an effective tool in a workshop. If you want to get uninterrupted service you have to take care of this tool. That means if the torque wrench falls in the floor accidentally the calibration can be disturbed. The wrench do not show any sign immediately but this will affect the function. As it is precious equipment it should be treated accordingly. It is necessary to check it against another wrench. Torque a bolt with one wrench and then try to torque the same bolt with the second wrench on the same torque setting. The process is easy. If the wrench pulls the bolt down farther before marking the same amount of torque, you know one is off. You have to repeat this process with the order of the wrenches reversed.
There is other scientific method of checking a digital torque wrench. It is wise to have it professional checked regularly. In the professional shops there will be several wrenches. You need to send the torques to the shops. If you need to use the torques regularly you should consider sending it in probably about once a year. If the torqueses are not working properly you have to go to the professionals immediately. To get more information you can read the digital torque wrench reviews.