What is the function of a strain gauge?

A strain gauge is a device that measures the amount of deformation or strain experienced by an object when subjected to an external force. Its primary function is to detect changes in resistance as the strain varies, which can be translated into an electronic signal for pressure measurement. Strain gauges are essential in various applications, including pressure transducers and load cells, where the measurement of force or pressure is critical.

In this context, it is relevant to note that the other options pertain to different types of sensors and measuring devices. Density measurements typically require specific instruments like hydrometers or densitometers, temperature measurements are accomplished with thermocouples or thermistors, and humidity levels are measured using hygrometers or capacitive humidity sensors. Each of these devices is designed to measure distinct physical properties, unlike a strain gauge, which is tailored specifically for quantifying mechanical strain leading to pressure readings.