Testing Pulse and Power Tools
You can test pulse and power tools in different ways:
1. Preferred Method (and quickest): Use a Torque Tester with a rotary torque sensor between the power tool and the actual application. This is the best way to test since you are using the actual joint as the test station. What the Torque tester displays is what the fastener “sees”.
2. Simulated Method: Always use a quality joint rate simulator (run down adapter) when testing power tools in a simulated application. Use Joint rate and Breakaway methods to obtain most accurate torque readings in a simulated rundown.
Note: Determining Joint Rate
You can use a Torque Tester (PTT or LTT) that features an angle mode operation with an rotary torque and angle sensor that has an angle encoder to determine the joint rate. The Torque Tester would display peak torque and angle in this mode. This is the most accurate method to
enhance simulated test applications.
Break Away Torque Method 1:
A common method of testing a previously fastened joint is to use a torque tester in peak mode with a torque screwdriver or wrench sensor like the SDX or ETX. Run the fastener down with the pulse or power tool. Apply additional torque to the fastener with the Torque Tester and a hand-held torque senors. As soon as the fastener starts to turn stop pulling on the wrench and note the reading on the Torque Meter. This is a “close” approximation of the torque achieved with the impulse tool (actually the true value is usually less than what is shown on the tester because of the torque necessary to overcome friction and operator influences). It is wise to take a number of these readings to get a true picture of what is really happening on the application joint. This will also give you a “feel” for how much variance you are getting from the output of the pulse or power tool. Remember that most pulse tools are no better than 10% accurate, and frictional variations create even more scatter in results (up to 30% or more).
Breakaway Torque Method 2:
Use a Torque Tester (PTT or LTT) with a rotary torque sensor that has an angle encoder built in. To check breakaway
(first movement) of a fastener: you set the low angle tolerance to a small value, usually 1 to 3 degrees, and the high angle tolerance to zero. Apply torque to an already tightened fastener, when the rotayr torque senors senses the threshold torque it will start looking for the fastener to move the number of degrees set as the low tolerance. When this number of degrees has been reached it will automatically capture the torque at that point and will disregard any further torque
input, even if you keep turning the fastener.
Note: The Breakaway torque methods can also be used with eletronic torque wrench that have the torque and angle encoder in it, like the E-TORC electronic torque angle wrench.
RTSX-A
Rotary Torque &
Angle Sensor
SDX
Torque Screwdriver
Sensor
PTT
Torque & Angle
Analyzer
