National Instruments 779994-01 Strain/Bridge Input Module

Often called the NI-9236, the National Instruments 779994-01 is a sophisticated 8-channel C Series Strain/Bridge Input Module made to accurately and effectively monitor dynamic strain. Impact testing and structural monitoring are two examples of applications that benefit greatly from this module's ability to do simultaneous high-speed measurements at up to 10 kS/s per channel.

For high-resolution data gathering across all channels, the 779994-01 has an analog prefiltering 24-bit Delta-Sigma ADC. Its integrated 350 Ω quarter-bridge completion and voltage excitation for quarter-bridge sensors streamline the strain gauge measurement setup. Synchronized measurements and accurate time correlation between channels are made possible by the internal master timebase of the module, which runs at 12.8 MHz with an accuracy of ±100 ppm.

The 779994-01's strong isolation capabilities, which include 1,000 V rms transient isolation and 60 VDC isolation, are among its primary features. This guarantees improved safety for the equipment and the operator as well as good common-mode noise rejection. The module has a temperature range of -40 °C to 70 °C for operation and -40 °C to 85 °C for storage. It is designed to function dependably under challenging conditions. It is appropriate for a variety of industrial environments because it can operate in humidity levels ranging from 10% to 90% RH.

Shunt calibration, a crucial step for precise strain measurements, is where the 779994-01 shines. Its highest gain error throughout the course of its operational temperature range is 0.2%, while its normal gain error at room temperature is 0.07%. A 100 kΩ resistance is used by the module for shunt calibration, resulting in an output value of -873.47 μV/V and a 15 ppm/°C temperature drift.

This instrument is rated for Pollution Degree 2 settings and satisfies IP40 ingress protection specifications. It can withstand severe mechanical stress, random vibrations of 5 g RMS from 10 Hz to 500 Hz, and shocks of up to 50 g for 3 ms, all while operating at altitudes of up to 5,000 meters.