Deformation measurement overview: Testing machine deformation measurement refers to a measuring system that measures the displacement and deformation of materials through a testing machine.
The deformation amplifier unit of the deformation measurement system is one of the main components of the testing machine. Its main function is to amplify the weak signal generated by the sensor, send it to the computer after processing, and record or display the deformation value suffered by the sample. .
Now most of the deformation units use a single chip 24-bit ultra-low noise analog-to-digital converter. This chip integrates signal amplification and A / D conversion in one. Because this set of deformation units has the characteristics of "single chip as the core and few peripheral circuits," this system has the characteristics of high accuracy, good stability, small linear error, and strong anti-interference ability. Reasonable design and good process layout make the stability of the amplifier very good. It is a single-chip computer unit connected to the amplifier. As the heart of the host, it is responsible for the amplifier's amplifier range conversion, data acquisition, data transmission, test mode selection, and liquid crystal display. Directly read digital quantization, and can pass these data through RS232. Port output, can also receive commands from other devices through RS232 port. Due to the use of a single-chip computer control, this unit has the function of automatic zero adjustment. When zeroing, just press the zero key on the main interface to automatically reset the whole process, and the zeroing time is extremely short.
Electronic universal testing machine
Deformation measurement technical parameters: Deformation measurement index parameters include measurement range, indication error, sensitivity, and resolution.
Measurement range-the range between the minimum and maximum dimensions of the material or component that the testing machine can measure through the measurement system.
Indication error——The difference between the recorded or displayed measurement value of the sample deformation value and the actual value of the measured value is called the indication error of the testing machine measurement system. The indication error is unavoidable, and its magnitude is within a specific range or a standard prescribed range.
Sensitivity of testing machine deformation measurement—The displacement rate of the sensitivity indicator relative to the measured change. Sensitivity is a sign of measuring physical instruments. The finer the sensitivity of the testing system of the testing machine, the higher the accuracy of the measurement results.
The resolution of the testing machine deformation measurement refers to the smallest measurable accuracy of the measuring data of the testing machine's photoelectric encoder. The higher the resolution, the more accurate the measurement results.
Deformation measurement works:
The strain gauge extensometer is composed of an elastic element and a strain gauge attached to it. When the extensometer moving arm is stressed, it will cause the elastic body to deform and change the resistance value of the strain gauge attached to it. The original balanced electricity The bridge loses balance and outputs a voltage signal that is proportional to the deformation. Because the electrical signal output by the extensometer is extremely weak, it must be amplified to reach the required value. This work is amplified and converted completely by the A / D converter and then sent The single-chip computer performs the processing and displays it in a direct-reading manner. At the same time, it is transmitted to the computer via RS232 for data processing.
Deformation measurement of the testing machine is a relatively important part of the testing and control system of the testing machine, and it is the key technical link of the testing machine. Selection of a highly reliable and stable deformation measuring instrument is one of the factors worthy of user consideration. Abnormal noise.