Strain Gauges

Conventional strain sensors are based on strain gage technology. In order to effectively measure the strain values in a force or load measurement application, a full, 4 element strain gage bridge circuit is utilized. The configuration is known as a Wheatstone Bridge Circuit. A Wheatstone Bridge has a very linear output in it’s midrange. That being considered +100% to -100% of range. Unfortunately, a Wheatstone Bridge becomes non-linear above the upper and lower extremes of range. Therefore, significant errors can result above the end points when attempting to take precision measurements. It is particularly important to take accurate measurements in some R&D or control applications. To avoid the mentioned error issues, PCB manufactures quartz piezoelectric strain sensors that output the same mV/microstrain sensitivity throughout the entire useful range. Thus, accuracy is improved and control requirements are enhanced that may occur at positive extremes of the measurement range. The models RHM240 and model 740B02 series sensors are the strain sensors for these applications.