Inexpensive Implementation of Many Strain Gauges

Arrays of metal film resistors would sense strains at multiple locations.

It has been proposed to develop arrays of strain gauges as arrays of ordinary metal film resistors and associated electronic readout circuitry on printed-circuit boards or other suitable substrates. This proposal is a by-product of a development of instrumentation utilizing metal film resistors on printed-circuit boards to measure temperatures at multiple locations. In the course of that development, it was observed that in addition to being sensitive to temperature, the metal film resistors were also sensitive to strains in the printed-circuit boards to which they were attached. Because of the low cost of ordinary metal film resistors (typically