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How to glue a resistance strain gauge
Nov 17, 2017

How to glue a resistance strain gauge

Paste Steps:

  1. Resistance strain gauge preparation

    Before the patch, the strain gage to be used for appearance inspection and resistance measurement. Appearance inspection can be carried out by the naked eye or with the help of a magnifying glass, in order to observe whether the sensitive gate has the rust-spot, the flaw, whether the arrangement is neat, the basement and the covering layer are damaged, the leader is intact. Resistance measurement JM3840 One-fourth Bridge measuring resistor. The purpose is to check whether the sensitive gate has a circuit breaker, a short circuit, and a resistance separation, for the common temperature compensation of a set of strain gauge, the difference in resistance should not exceed ±0.5. The sensitivity coefficients must be the same for the strain gauges of the same measurement.

  2. Component Surface Treatment

    For steel and other metal components, the first is to remove the surface paint, oxidation layer and dirt, and then grind flat or file flat, and polished with fine sand cloth. This process is often referred to as "sanding". Polished finish should reach ▽5 around. For very smooth members, the sand cloth should be 45° along the direction of the intersection to sharpen some grains to enhance the cohesion. The grinding area is about 5 times times the strain Gage area. After grinding, use a needle to gently draw the exact position of the patch. The final process of surface treatment is cleaning. That is, clean cotton yarn or absorbent cotton balls dipped in acetone or other volatile solvents on the patch site repeatedly scrub until the cotton ball to see dirt.

  3. Gluing

    Patch process with the use of binders different, with 502 adhesive patch process is, after the cleaning agent Volatilization, first in the patch position drop a little 502 glue, with the back of the strain gauge to rub the glue, and then use tweezers to adjust the strain gauge, position and angle. After positioning, in the strain gauge on a layer of polyethylene or tetrafluoroethylene film, gently squeeze out the extra glue and bubble to the initial curing after the glue can be loosened. The pasted strain Gage should ensure the position is accurate, the bond is firm, the glue layer is uniform, the bubble is clean and tidy.

  4. Welding and fixing of conductors

    After the bonding agent is initially cured, the weld line can be carried out. static measurement at room temperature can use double core and multi ply copper plastic wire as conductor, dynamic measurement using three-core or quad-core shielded cable as wire. The connection between the strain gauge and the wire is best through the terminal terminals, and the solder joints ensure no virtual welding. The wire is best to be fastened with the specimen, and the wire ends are labeled according to the number of the measuring point.

  5. Patch Quality Inspection

    The quality inspection of the patch includes appearance inspection, resistance and insulation resistance measurement. The appearance examination mainly observes whether the patch position is correct, Change has the damage, pastes whether is firm and has the bubble and so on. Measurement of resistance value can be checked for open circuit, circuit. Insulation resistance is the most important index. The insulation depends on the base of the strain gage, and the strain gage with poor adhesion or insufficient curing is often low in insulation resistance.

  6. Protection of strain gauge and wire

    Strain gauge damp will reduce the insulation resistance and bonding strength, severe when the sensitive grid corrosion; acid, alkali and oil immersion may even alter the physical properties of the substrate and binder. In order to prevent the air free water and rainwater, dew immersion, in a special environment to prevent the intrusion of acid, alkali, oil and other impurities, to have been fully dry, cured, and have been welded wire strain gage, immediately coated with protective layer. Commonly used room temperature protective agent is: 1. Vaseline; 2. Bee; 3. Mixture of lime, oil and rosin; 4. Epoxy resin.