Reliant Technology LLC.
2334 E Boulder Street
Colorado Springs, CO 80909 USA
+1-719-694-8040
Phone: 719.694.8040
Fax: 888.809.3867
info@extensometry.com
All strain gaged transducers (load cells, extensometers, etc.) are considered "passive" instruments. Unlike active sensors, passive sensors
typically require some sort of electrical energy (excitation) to provide an electrical output signal. Extensometers are typically excited (powered)
by a voltage of 5 or 10 VDC (although, some signal conditioners do use 5 or 10 VAC). As a result, the calibrated output of such sensors is often
expressed in millivolts per volt (mV/V). For example: an output of 2.451 mV/V means the output at full scale, with 10 volts excitation will be 24.510 millivolts. The
inspection certificate provided with your extensometer will include this data.
Since strain gage based extensometers are passive, they do require some external electronics for output. The electronics provide the excitation voltage
and typically amplify the signal to a high level, DC voltage. This high level output is used for direct readout or control of the test machine. In more
advanced systems the voltage output can be converted into engineering units (% strain, etc.). For use with chart recorders, the output is typically set
to a specified strain/in [strain/cm] on the graph paper. Your Reliant extensometer should only be used for tests within its rated temperature range.
Operation outside of this range can cause permanent
damage to the extensometer and or cable.