Real-time video extensometer
This disclosure relates to a real-time video extensometer. Typically, the apparatus of the disclosure combines the image source, data processing and electrical output on to a single processing board in order to achieve high frequency images and low latency times on data flow. Further, the video processing engine processes the image on a pixel basis and updating the output the intermediate extension/strain result so that after receipt of the final image pixel, a final extension/strain value is achieved and immediately output for evaluation.
1. An extensometer for measuring extension/strain on a testing specimen, comprising:
an imaging device for generating image data of a testing specimen which is subjected to a stress-inducing load;
a calculating device, including a microprocessor and a logic device, wherein the logic device receives the image data of a testing specimen, determines movement of targets on a testing specimen and determines extension/strain from the determined movement of targets, the microprocessor, the logic device, and a communication path between the microprocessor and the logic device being on the same circuit board; and
an output device for outputting the determined extension/strain in real-time.
2. The extensometer of claim 1 further including an input for receiving a trigger or sync signal to initiate operation or time-stamping.
3. The extensometer of claim 1 wherein extension/strain is determined in two orthogonal directions.
4. The extensometer of claim 1 wherein extension/strain is determined in the axial direction and in the transverse direction.
5. The extensometer of claim 1 further including a constant density air tube through which the imaging device views the testing specimen.
6. The extensometer of claim 5 wherein the constant density air tube includes at least one fan, thereby creating a virtual airtube.
7. The extensometer of claim 6 wherein the at least one fan of the constant density air tube is at least partially controlled by the same circuit board.
8. The extensometer of claim 1 further including an ethernet connection.
9. The extensometer of claim 1 further including an illumination device for illuminating the testing specimen.
10. The extensometer of claim 1 wherein the illumination device emits polarized light.
11. The extensometer of claim 1 further including an auxiliary camera link connector input for receiving an image of a testing specimen which is subjected to a stress-inducing load.