Welcome to the Western Regional Strain Gage Committee (WRSGC)
We are a Technical Division of the National Society for Experimental Mechanics (SEM)

The strain gage was invented between 1936 and 1938 by two different individuals, almost simultaneously. They were situated on the east and west coasts of the United States and had no contact with one another. Professor Arthur C. Ruge of the Massachusetts Institute of Technology (MIT) was one of the inventors, and the other was Edward E. Simmons of the California Institute of Technology (Caltech). Professor Ruge submitted the bonded wire ‘resistance strain gage’ idea to the MIT patent committee. The response from the MIT patent committee read: ‘…this development is interesting; the Committee does not feel that the commercial use is likely to be of major importance… any rights which the Institute may have in this invention should be waived in your favor…’

Professor Ruge, along with his colleague Professor Alfred V. DeForest, approached the heavy machine manufacturer Baldwin-Southwark Corp. to consider the production and sale of strain gages under a license agreement. Baldwin-Southwark’s initial response to Ruge-DeForest’s license offer was: ‘We are in the locomotive business and are not going to make postage stamps.’ After an impressive demonstration of the strain gage’s performance in 1939, a collaboration began between Ruge-DeForest and Baldwin-Southwark. In 1941, they received their first sizable order for 50,000 units of the SR-4 gage (the initials S and R honor the inventors). The strain gage invention was patented by the United States Patent Office on June 6, 1944.

In 1955, Ruge and DeForest sold their interests to Baldwin-Lima-Hamilton (BLH). To accelerate the industry’s acceptance and use of the new SR-4 foil strain gage (shown below).

Fred Singdale of BLH formed a technical group consisting of major users of strain gages. Below is the invitation that Professor Peter Stein received to attend the first SR-4 Committee Meeting, which took place on April 18, 1956. The SR-4 Committee later became known as the Western Regional Strain Gage Committee. This group not only promoted the use of foil strain gages but also influenced manufacturers to conduct new research and development programs, advancing strain gage technology in general.

WRSGC was established to promote a free interchange of information about strain measurement techniques including:

• State-of-the-art strain gage research
• Development & application of strain gages for
  all environments
• Strain measurement & connection techniques
• Strain gage based transducers
• Signal conditioning, data acquisition systems &
  real-time display