Torque testers are devices that measure and calibrate torque in tools, parts and equipment. They typically determine the maximum and minimum torque as well as the accuracy of the actual output as compared to the displayed amount.
Though similar in purpose, they are different from dynos. Some have a temperature compensation feature that prevents a mistaken reading by accounting for the effect increasing or decreasing temperatures can have on a measurement.
Modern torque testers are able to measure torque in clockwise and counterclockwise directions as well as convert the reading into a number of units. Common outputs and arrangements for these devices include analog voltage, analog current, modulated frequency, switch or alarm, serial and parallel.
In addition, some are designed for use in difficult environments and have increased resistance to shock and vibration in order to take an accurate and fast reading. Many torque testers are handheld electronic devices with a small screen to display the readings.
The components are encased in plastic and several input buttons allow the user to select the preferred options. Torque testers are an important device that maintains safe and efficient conditions.
They measure and calibrate tools such as torque wrenches and electric screwdrivers as well as machines and industrial equipment like automotive engines and centrifugal pumps.
Torque testers have three main components. A transducer, or load cell, is a device that converts force into an electrical signal. There are three main ways of doing this. Magnetoelectric sensors use any detected changes in their own magnetic field to create a signal, which is different from eddy current dynamometers, though both use magnets to measure torque.
Piezoelectric sensors are compressed by the force of the torque, thus generating a charge. A strain gauge becomes deformed when the force from the torque travels through an assembly and distorts it; the distortion is then converted into electric signals and amplified.
There are two main kinds of sensors that testers use: reaction and rotary. Reaction torque testers use a stationary transducer while rotary testers use a rotating transducer to take readings. After an algorithm calculates the force applied to the transducer that produced a current of that magnitude, the results are displayed on a screen.
The display and transducer may be held in the same housing or an external transducer can be connected to a portable display. During calibration, a joint simulator, or rundown fixture, is used to test power tools.
The joint simulator is placed on top of the transducers with an adapter bit to attach the two. Springs or washers are used to simulate how a tool would behave while operating in a normal setting.