| Basic Knowledge |
| The stick of strain gages |
According to strain gage, glue preparation, use environment discrepancy, the stick method of strain gage is different. Here we take the normal temperature indoor survey as the example, choose the conventional type strain gage (KFG strain gage with lead wire), quick drying strain gage cement and Low-carbon steel test film.
1、Choose strain gage
According to the UUT and purpose, we must choose the right strain gage. For example, the strain gage's kind, length and reference strain gage coefficient of heat expansion, these parameters are what we need to think of.
2、Remove rust and protective film
Use the emery cloth to burnish the position which being stick by strain gage (larger than the area of strain gage), until remove the paint, rust, gild and so on.
3、Confirm stick position
Use the horniness pencil above 4H to mark the position where need to measure strain along with the stress direction. Be careful not Leave the deep scratch behind when using.
4. Degreasing and clean surface
Use the technical tissue dip with acetone solvent to clean the stick position. During the process of cleaning, focus to one direction. If you rub back and forth, it is unable to clean the filth.
5、Smear glue/ cement
Before you smear the glue/ cement (CC-33A) to the reverse side of strain gage, notice the face of positive and negative of it. Do not use the way of smear the board, because the first part of glue will present hardening, and cause the coherency to drop.
6、Stick
Put the strain gage with cement on the central position of mark immediately.
7、Press
Place the polyvinyl resin piece on the stick strain gage, and press on it with finger. The step 5, 6, and 7 must finish in one uninterrupted motion. It will cause the coherency to drop a lot if you readjust the position.
8、Finish
After press about one minute, take off the polyvinyl resin piece, and make sure stick reliably or not. Then we finish the whole stick process.
In order to let the glue/ cement harden completely and achieve a better effect, you'd better lay aside the strain gauge about 60 minutes.
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