Achieving precise and accurate strain measurement

Unless the environmental conditions of an application remain static, it is critical to know the temperature at the strain gauge location to correct any change in resistance of the gauge due to temperature fluctuation (thermal output). Even as strain gauge manufacturers become more skilled in minimising thermal output by controlling the metallurgy and heat treatment of the alloys used to produce the resistance grid, temperature monitoring to improve measurement accuracy continues to be of great importance.

It is important to Micro-Measurements to characterise the thermal output of its strain gauges, and it provides the appropriate fourth order polynomial variables derived from the thermal output of each batch of gauges constructed from well-known materials. These variables are critical to minimising the effect of thermal output on test data, a factor so critical to accurate strain measurement that Micro-Measurements offers temperature measurement capabilities in all its data acquisition systems - either via thermocouple inputs or an RTD.

“Until now, customers needing to measure strain and temperature (such as in the experimental stress analysis and OEM transducer markets) have had to install both a strain gauge and a separate temperature sensor,” said Darryl Peterson, Micro-Measurements Technical Sales Manager. “A key consideration in installing these components is the sensor’s proximity to the strain gauge, which must be very close to accurately measure the temperature of the gauge site. With our Sensor Gage, both components are installed in a single bonding operation, ensuring that the temperature sensor is at the best possible location to make the most accurate measurement.”