Strain sensors are generally sensitive to gate, substrate, lead, cover films and other components. Sensitive gate by the diameter of 0.01-0.05mm, high resistivity of the filaments made of grid-like bending, it is actually a resistance element, is the feeling of strain gauges, strain-sensitive component parts. Qi sensitive gate will be fixed with adhesive in the substrate. The role of basement structures on the response should be to ensure the accurate transmission of the sensitive gate up. So it must be very thin, generally 0.03-0.06mm, so that it can and sample and the sensitive strain gauges sense the basic structural grid firmly bonded together. Further, it should have good insulating properties, moisture resistance and heat resistance properties. Substrate materials are paper, film, glass fiber cloth. Paper is soft, easy to paste, strain limit the advantages of large and cheap, but poor temperature humidity, temperature lower than 70 ℃ generally used under the. In order to improve the durability and the use of temperature humidity can be impregnated with phenolic resin adhesive temperature may be raised to 180 ℃, and the time has good stability, suitable for measuring force and other sensors used. Film substrate by epoxy resin, phenolic resin, polyester resin and polyimide film made from organic adhesives, film substrate has better flexibility than paper, moisture resistance and durability, and the temperature can be up to 100-300 ℃. Capability of glass fiber cloth temperature 400-450 ℃, and more used in the temperature or high temperature strain gauge base. Lead role is to be sensitive gate resistance element connected with the measurement circuit, generally 0.1-0.2mm tinned copper wire made of low resistance, and with the sensitive gate 2 output Duanxiang welding.
In the test, the strain gage adhesives firmly affixed to the surface of parts being tested, with the sample deformation, strain gauge sensitive gate be given the same deformation, thus resulting resistance to change, and This resistance change is the ratio of the specimen should become, so if by some change in resistance measurement circuit to convert this voltage or current changes, and then use the display and recording instrument to record their shows, will be test cases that should be variable size.