National Instruments PXIe-4339 PXI Strain/Bridge Input Module

The PXIe‑4339 (Part Number: 783531-01) is a universal Strain/Bridge Input Module by National Instruments, which is suitable for test cell installations that require both accuracy and flexibility. The NI PXIe-4339 Strain/Bridge Input Module is configurable through software. All channels can take bridge-based measurements and direct voltage measurements. This module has eight input ranges in ratio metric mode and four input ranges in voltage mode. The PXIe‑4339 also features per-channel wide bandwidth analog outputs, along with programmable excitation, TEDS support, and digital filtering. The NI PXIe-4339 can operate at a maximum sample rate of 25.6 kS/s.

The PXIe-4339 module uses two methods to correct the resistance errors. One is remote sensing and the other is shunt calibration. The NI PXIe 4339 has a built-in remote sensing system, which continuously and automatically corrects for errors in excitation leads. Remote Sensing is most appropriate for half- and full-bridge sensors.  Besides, it is exclusively used in applications that have long wires and/or a small gauge. The resistance in the wires connects the excitation voltage to the bridge and causes a voltage drop. This voltage drop is called gain error. While using the remote sensing system, the PXIe-4339 can compensate for this gain error.

The NI PXIe-4339 Strain/Bridge Input Module has shunt calibration circuitry, which consists of a software-controlled switch. This switch is used in conjunction with the shunt calibration resistors. Shunt calibration can rectify errors from the resistance of the excitation wiring and correct errors from the wiring in the individual resistors of the bridge. There is sufficient resistance in the wiring to the sensor, so shunt calibration is best with three-wire quarter-bridge sensors.