Adhesives: Strain Gage Accessories for Applications and Installation 

Because a strain gage can perform no better than the adhesive with which it is bonded to the test member, the adhesive is a vitally important component in every strain gage installation. Although there is no single adhesive ideally suited to all applications, Micro-Measurements offers a wide selection of adhesives to cover the spectrum of stress analysis testing, and for use in transducer manufacturing. Micro-Measurements adhesives are specially formulated and selected for highest performance under the recommended environmental conditions, and are packaged to provide for ease of mixing and application

 

Each adhesive is accompanied by specific instructions for its proper handling—storage, mixing, application, curing, and, if appropriate, post-curing. The adhesive containers are also dated to assure freshness of the contents

 

Since different adhesives are intended for different types of applications and different environmental conditions, it is obviously important to select the most appropriate adhesive for each strain measurement task. The table below lists all of the Micro-Measurements adhesives, while the table on the following page is provided as a guide for selecting the most appropriate adhesive for compatibility with a particular strain gage series and test environment.

Strain Gage Adhesives Chart

                                 
    | -500 F | -320 F | -150 F       | +32 F     | +200 F   | +400 F   | +575 F | +750 F

 

Room
Temperature
Cure

  M-BOND 200 |   |   |                   |     |   |   |
  |   |   |         |       |     |   |   |
M-BOND AE-10 |                             |   |   |
  |   |   |         |     |     |   |   |
M-BOND GA-2 |                       |     |   |   |
  |   |   |         |     |     |   |   |
M-BOND A-12 |   |   |                   |     |   |   |
  |   |   |         |     |     |   |   |
M-BOND 300 |   |   |                     |   |   |
  |   |   |         |     |     |   |   |
RTC-2 |                             |     |   |   |
    |   |   |         |     |     |   |   |
    | -300 C   | -200 C   | -100 C       | 0 C     | +100 C   | +200 C   | +300 C   | +400 C
         

 


 


 


 


 

    | -500 F  
  | -320 F
 
  | -150 F
     
  | -32 F
   
  | +200 F
 
  | +400 F
  | +575 F   | +750 F

 

Elevated
Temperature
Cure

  M-BOND 610 |             |                               |   |
  |   |   |         |     | |   |   |   |
M-BOND 600 |           |                               |   |
  |   |   |         |     | |   |   |   |
M-BOND 43-B |         |                     |   |     |   |
  |   |   |         |     | |   |   |   |
M-BOND 450 |         |                               |   |
  |   |   |         |     | |   |   |   |
M-BOND AE-15 |         |   |                     |     |   |
  |   |   |         |     |     |   |   |
M-BOND GA-61 |       |   |                     |     |   |
  |   |   |         |     |     |   |   |
DENEX #3 |                                   |   |   |
  |   |   |         |     |     |   |   |
EPOXYLITE 813 |   |                                   |
  |   |   |         |     |     |   |   |
P ADHESIVE |         |                                 |
  |   |   |         |     |     |   |   |
QA-500 |   |                               |   |
  |   |   |         |     |     |   |   |
EPY-500 |       |                               |   |
    |   |   |         |     |     |   |   |
    | -300 C | -200 C | -100 C       0 C     +100 C   +200 C   +300 C +400 C

 

 

 

Strain Gage Adhesives List

     
M-BOND 200   Most widely used general-purpose adhesive. Easiest to handle. Fast room-temperature curing.
     
M-BOND AE-10   General-purpose adhesive that is highly resistant to moisture and most chemicals. Room-temperature curing.
     
M-BOND AE-15   Similar to AE-10. Recommended for more critical applications, including transducer gaging. Moderately elevated-temperature curing.
     
M-BOND 610   Used primarily in stress analysis applications over a wide temperature range, and in precision transducers. Elevated-temperature curing.
     
M-BOND 600   Similar to 610, but faster reacting. Can be cured at somewhat lower temperatures than 610.
     
M-BOND 43b   Normally used in precision transducers. Highly resistant to moisture and chemical attack. Elevated-temperature curing.
     
M-BOND GA-2   Special-purpose adhesive primarily used on very rough and irregular surfaces. Room-temperature curing.
     
M-BOND GA-61   Special-purpose adhesive with a higher operating temperature range than GA-2, and more viscous. Also used to fill irregular surfaces and to anchor leadwires. Elevated-temperature curing.
     
M-BOND A-12   Special-purpose, very high-elongation adhesive. Used only when other adhesives cannot meet elongation requirements. Elevated-temperature curing.

 

 

 

 

Ceramic Adhesives


 

At extremely high temperatures, all insulating materials suffer from a decline in their insulating properties.  Ceramic cements, while very robust at elevated temperature, also exhibit this characteristic.  While the reduction in insulation resistance to ground is not permanent, it does decline to the point where it will influence signal stability and accuracy.  The effectiveness of the cement as an insulator is under the direct control of the installer.  The thickness and consistency of the base coat, which becomes the “backing” for the free filament strain gage, is critical to the quality of the installation. 

 

Additionally, this layer is the media, which transmits strain from the test article to the strain gage filament.  If the layer is too thick, it will crack when strained.  If it is too thin, the insulation resistance to ground will be insufficient at elevated temperature.  The ideal base coat thickness is 0.003”.  When properly installed, some of the free filament gages can collect valid data to 2100°F and under ideal conditions; data can be recorded at even higher temperatures.  It is incumbent upon the technician / engineer to develop the necessary skill set to make the installation and to verify the installation quality before taking data.

 

 

 

Ceramic Adhesives Chart

  | -500 F | -320 F | -150 F   | +32 F   | +200 F   | +400 F | +575 F | +750 F | +930 F | +1,100 F | +1,300 F | +1,475 F | +1,650 F | +1,800 F  
  |   |   |           |     |   |     |   | |   | | | |  
GC CEMENT |                                                   |  
  |   |   |     |     |     |   |     |   | |   | | | |  
PBX CEMENT |                                             | | | |  
  |   |   |     |     |     |   |     |   | |   | | | |  
SAUREISEN #8 CEMENT |                                                   |  
  |   |   |     |     |     |   |     |   | |   | | | |  
H Cement |                                                   |  
  |   |   |     |     |     |   |     |   | |   | | | |  
HG-1 (TEC of steel) |                                               | | |  
  |   |   |     |     |     |   |     |   | |   | | | |  
NCC-3 |                                               | | |  
  |   |   |     |     |     |   |     |   | |   | | | |  
WC-16 (low TEC) |                                               | | |  
  |   |   |     |     |     |   |     |   | |   | | | |  
  -300 C -200 C -100 C   0 C     +100 C   +200 C +300 C +400 C +500 C +600 C +700 C +800 C +900 C +1,000 C

 

 

 

 

Ceramic Adhesive List

EPOXYLITE 813   Used for long term, high temperature applications requ
     
P ADHESIVE   Single-part solvent thinned polyimide adhesive. Excellent for long-term high temperature applications.
     
GC CEMENT   Single-part ceramic cement used for free-filament gages. Recommended for use on low TCE materials, such as carbon.
     
PBX CEMENT   Two-part ceramic cement/coating used for free-filament strain gages. Good adhesion to most metals.
     
SAUREISEN #8 CEMENT   Single-part chemical setting zircon-based cement used for free-filament strain gages. High electrical insulation and thermal conductivity.


 

 

 

alt
VIDEOS

Explore our extensive collection of tutorials and informational videos on a variety of strain measurement topics.

alt
STRAINTALKS

Explore our free education seminars aimed at helping Design and Test Engineers understand strain gage theory selection, preparation, performance, installation, configuration, and more.

alt
STRAINBLOG

Questions and answers on the go! Listen to Micro-Measurements experts explain the many facets of strain gage technology.

alt
TRAINING

Benefit from an extensive series of regularly scheduled, hands-on technical workshops and short courses.