Film Peel Tester Measurement Principle
Dongguan Haida Instrument 400-071-1808/0769-89280808
1. The measurement of the force value of the tensile testing machine is completed by measuring the force sensor, amplifier and data processing system. What is the measuring principle of the tensile testing machine ? The most commonly used force sensor is a strain gauge sensor. The so-called strain gauge sensor is a device that can convert certain mechanical properties into electrical output by using strain gauges, elastic components, and certain accessories (compensation components, shields, wiring jacks, and loaders). Strain gauge pull, pressure sensors in various types of national and foreign watches, mainly cylindrical force sensor, spoke force sensor, S double hole type sensor, cross beam type sensors.
According to data mechanics, under the premise of small deformation, the strain ε at one point of an elastic element is proportional to the force of the elastic element, and it is also proportional to the change of elasticity. Take the S -type testing machine sensor as an example. When the sensor is subjected to the tensile force P , the strain gauge is attached to the measuring circuit due to the fact that the strain gauge is attached to the external surface of the elastic component and the strain of the elastic component is proportional to the magnitude of the external force P. , you can measure its output voltage, and then measure the size of the force.
In short, the external force P causes deformation of the strain gauges in the sensor, which causes the bridge to be unconvinced, and then causes a change in the output voltage of the sensor. After measuring the change in the output voltage, we can know the size of the force. Tensile testing machine measurement In general, the sensor output signal is very long and weak, mortal only a few mV , if we directly measure the signal, the length of the hard, and can not meet the high Accuracy measurement requirements.
Therefore, the weak signal must be enlarged by an amplifier, and the voltage of the amplified signal can reach 10V . The signal at this time is the signal of imitating the signal. This analog signal is multi-channel switch and A/D conversion. The chip is changed to a digital signal, and then the data is processed. At this point, the measurement of the pull test machine force comes to an end.
2. The measurement of the deformation is measured by a deformation measurement installation, which is used to measure the deformation of the sample during the course of the experiment. There are two chucks on the installation, connected via a series of biographies and an [optical encoder] mounted on the top of the measuring device. When the interval between the two chucks changes, the axis of the photoelectric encoder is twisted. Photoelectric encoder will have a pulse signal output. The disposal of this signal by the disposer will produce the deformation of the sample.
3. The measurement of the beam displacement is roughly the same as the deformation measurement, and the displacement of the beam is obtained by measuring the output pulse number of the photoelectric encoder.