Question

Which of the following is the correct definition for Gauge factor?

(a) (incremental change in resistance due to strain/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length)

(b) (resistance of an unstretched wire/incremental change in resistance due to stress)*(unstretched length of wire/incremental change in length)

(c) (incremental change in resistance due to stress/resistance of an unstretched wire)*(incremental change in length/unstretched length of wire)

(d) (incremental change in resistance due to stress/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length)

The question was asked in exam.

The above asked question is from Implantable Telemetry Systems in portion Biomedical Telemetry of Biomedical Instrumentation

Answer 1

Right option is (d) (incremental change in resistance due to stress/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length)

Easiest explanation: Gauge factor is defined as (incremental change in resistance due to stress/resistance of an unstretched wire)*(unstretched length of wire/incremental change in length). Gauge factor gives information on the expected resistance change or output signal at maximum permissible elongation. The gauge factor determines to a large extent the sensitivity of the wire when it is made into a practical strain gauge.