PXIe-4331 High-Speed Strain and Bridge Input Module
The PXIe-4331 is an 8-channel, 24-bit PXI Express strain and bridge input module designed for dynamic strain, load, force, pressure and torque measurements. It combines high-speed simultaneous sampling with integrated bridge signal conditioning.
All eight channels sample simultaneously at rates up to 102.4 kS/s per channel. Each channel provides independently programmable excitation, remote sensing, bridge completion, digital filtering and shunt calibration.
Key Features of the PXIe-4331
- 8 simultaneous strain and bridge input channels
- 24-bit analog input resolution
- 102.4 kS/s maximum sampling rate per channel
- Dedicated delta-sigma ADC for every channel
- Full-, half- and quarter-bridge support
- 120 Ω, 350 Ω and 1 kΩ quarter-bridge completion
- Independent programmable excitation per channel
- Excitation voltage settings from 0.625 V to 10 V
- Remote excitation sensing
- Internal and external shunt calibration
- Per-channel anti-alias and digital filtering
- PXI Express synchronization and high data throughput
- NI-DAQmx driver support
PXIe-4331 Technical Specifications
| Product Model | PXIe-4331 |
|---|---|
| Part Number | 781345-01 |
| Product Type | PXI Express Strain and Bridge Input Module |
| Input Channels | 8 differential bridge input channels |
| ADC Resolution | 24 bit |
| ADC Type | Delta-sigma with analog prefiltering |
| Sampling Mode | Simultaneous |
| Maximum Sample Rate | 102.4 kS/s per channel |
| Input Ranges | ±25 mV/V and ±100 mV/V |
| Bridge Configurations | Full, half and quarter bridge |
| Quarter-Bridge Completion | 120 Ω, 350 Ω and 1 kΩ |
| Excitation Type | Balanced constant differential voltage |
| Excitation Settings | 0.625 V, 1 V, 1.5 V, 2 V, 2.5 V, 2.75 V, 3.3 V, 5 V, 7.5 V and 10 V |
| Shunt Calibration Resistors | 33.333 kΩ, 50 kΩ and 100 kΩ |
| Common-Mode Input Range | ±2 V |
| Common-Mode Rejection | 85 dB, DC to 1 kHz |
| FIFO Buffer | 1,023 samples |
| Data Transfers | DMA and programmed I/O |
| Bus Type | PXI Express |
| Operating Temperature | 0°C to 55°C |
PXIe-4331 Part Number and Accessories
| Item | Part Number | Description |
|---|---|---|
| PXIe-4331 | 781345-01 | 8-channel, 24-bit, 102.4 kS/s strain and bridge input module |
| TB-4330 | 781347-01 | Front-mount terminal block for PXIe-4330 and PXIe-4331 |
| RM-24999 | 785840-01 | Rack-mount terminal block for PXIe-4330 and PXIe-4331 |
| SH96F-96M-5 | 786341-01 | 1 m shielded cable for connecting the module to RM-24999 |
| SH96F-96M-5 | 786341-03 | 3 m shielded cable for connecting the module to RM-24999 |
| SH96F-96M-5 | 786341-05 | 5 m shielded cable for connecting the module to RM-24999 |
The TB-4330 mounts directly on the front of the module. The RM-24999 is intended for rack-mounted systems and requires a compatible SH96F-96M-5 shielded cable.
High-Speed Simultaneous Sampling
The PXIe-4331 provides a dedicated 24-bit ADC for each input channel. All eight channels can sample simultaneously at rates up to 102.4 kS/s per channel.
This high sampling rate allows the module to capture rapidly changing strain, impact, vibration-related bridge signals and dynamic mechanical loads while maintaining time alignment across every channel.
24-Bit Measurement Resolution
The 24-bit delta-sigma ADC architecture provides the resolution required for low-level bridge outputs. Analog prefiltering and digital filtering help reduce unwanted noise and out-of-band signal components.
The combination of high resolution and high sampling speed makes the PXIe-4331 suitable for both static and dynamic bridge-based measurements.
Full-, Half- and Quarter-Bridge Support
The module supports full-, half- and quarter-bridge configurations. Bridge type can be selected independently for each channel using NI-DAQmx or compatible measurement software.
Integrated bridge completion reduces the external components required for quarter- and half-bridge strain gauge measurements.
Quarter-Bridge Completion
Internal quarter-bridge completion is available for 120 Ω, 350 Ω and 1 kΩ strain gauges. The selected completion resistance must match the nominal resistance of the connected gauge.
Incorrect bridge completion can cause large offsets, scaling errors or invalid measurements.
Programmable Excitation Voltage
Each PXIe-4331 channel includes an independently programmable balanced excitation source. Available settings include 0.625 V, 1 V, 1.5 V, 2 V, 2.5 V, 2.75 V, 3.3 V, 5 V, 7.5 V and 10 V.
The appropriate excitation voltage depends on the bridge resistance, configuration, sensor power limits and required signal sensitivity.
Remote Excitation Sensing
Remote sensing measures the excitation voltage directly at the bridge sensor and compensates for voltage loss in long excitation wires.
This improves measurement accuracy for remotely installed load cells, pressure sensors and strain gauges where cable resistance may otherwise reduce the actual bridge excitation.
Shunt Calibration
The PXIe-4331 supports software-selectable internal and external shunt calibration. Available internal shunt resistor values include 33.333 kΩ, 50 kΩ and 100 kΩ.
Shunt calibration introduces a known electrical imbalance into the bridge. The resulting response can verify the measurement channel, wiring, completion resistance and software scaling.
Anti-Alias and Digital Filtering
Each channel includes analog prefiltering and digital anti-alias filtering. These filters reduce high-frequency noise and help prevent out-of-band signals from appearing incorrectly in the measured data.
The effective filter response depends on the selected sampling rate and should be considered when measuring impacts, transients and other dynamic events.
Dynamic Strain Measurement
The 102.4 kS/s sampling rate enables the PXIe-4331 to capture dynamic strain events that may be missed by slower bridge modules. Typical examples include impact tests, vibration-related strain, rapid load changes and structural transients.
Simultaneous sampling maintains the timing relationship between strain gauges installed at different locations on the test structure.
Load, Force and Pressure Measurements
Full-bridge load cells, force transducers and bridge-based pressure sensors can be connected directly to the module. Sensor sensitivity values are used to convert the measured mV/V signal into engineering units.
Remote sensing and shunt calibration help verify measurement accuracy, particularly when sensors are installed at a distance from the PXI system.
Torque Measurements
The PXIe-4331 supports bridge-based torque transducers requiring high-speed acquisition. Its simultaneous sampling architecture allows torque data to be correlated with strain, force, position or other synchronized measurements.
Correct excitation, sensitivity, bridge configuration and physical scaling must be entered for accurate torque results.
Typical Applications
- Dynamic strain measurement
- Impact and crash testing
- Structural and fatigue testing
- Load cell and force measurement
- Bridge-based pressure measurement
- Torque sensor acquisition
- Automotive component validation
- Aerospace structural testing
- Material and mechanical testing
- High-speed production testing
NI-DAQmx Software Support
The PXIe-4331 is supported by NI-DAQmx, which provides configuration for bridge type, excitation, completion resistance, shunt calibration, sampling, triggering, filtering and engineering-unit scaling.
Applications can be developed with LabVIEW, Python, C, C# and other supported programming environments.
FlexLogger Integration
FlexLogger can configure and record strain, load, force, pressure and torque measurements without requiring a complete custom application. Users can define sensor sensitivities, engineering units, sample rates, alarms and logging conditions.
Its interactive workflow is useful for structural validation, mechanical testing and synchronized multichannel data logging.
PXI Express System Integration
The PXIe-4331 requires a compatible PXI Express chassis and controller. Multiple modules can be synchronized to create larger dynamic strain and bridge measurement systems.
Visit the NI PXI Modules category to explore related PXI measurement hardware.
Troubleshooting the PXIe-4331
The module is not detected
Confirm that the PXIe-4331 is installed in a compatible PXI Express slot. Check the chassis controller, PXI Platform Services and NI-DAQmx installation.
The bridge measurement has a large offset
Verify the bridge configuration, completion resistance, sensor wiring and initial bridge balance. Inspect the strain gauge or sensor for damage.
The measured strain has the wrong polarity
Check the gauge orientation and AI+ and AI− connections. Correct the wiring or apply the appropriate software scaling direction.
The excitation voltage is lower than expected
Confirm that the selected excitation is compatible with the bridge resistance and configuration. Check for excessive cable resistance, sensor loading or a short circuit.
Dynamic signals appear attenuated
Review the sampling rate and filter response. Ensure the configured measurement bandwidth is sufficient for the expected signal frequency.
Shunt calibration produces an unexpected result
Check the selected shunt resistor, bridge completion, gauge resistance and software scaling. Confirm that all sensor connections are secure.
PXIe-4331 Comparison
| Model | Channels | Resolution | Maximum Rate | Primary Use |
|---|---|---|---|---|
| PXIe-4331 | 8 | 24 bit | 102.4 kS/s per channel | High-speed dynamic strain measurements |
| PXIe-4330 | 8 | 24 bit | 25.6 kS/s per channel | General bridge and strain measurements |
| PXIe-4339 | 8 | 24 bit | 25.6 kS/s per channel | Strain and bridge measurement systems |
| PXIe-4340 | 4 | 24 bit | 25.6 kS/s per channel | LVDT and RVDT sensor measurements |
Recommended Related Products
- PXIe-4330 – 8-channel bridge module with a 25.6 kS/s sampling rate
- PXIe-4339 – 8-channel strain and bridge input module with multiple terminal options
- PXIe-4340 – dedicated input module for LVDT and RVDT sensors
- PXIe-4468 – dynamic signal acquisition module for vibration and acoustic measurements
- PXIe-1092 – PXI Express chassis for modular measurement systems
Selecting the PXIe-4331
Choose the PXIe-4331 when an application requires high-speed simultaneous acquisition of strain gauges, load cells, pressure sensors or torque transducers at rates up to 102.4 kS/s per channel.
For lower-bandwidth bridge measurements, the PXIe-4330 may provide a more economical solution. For LVDT or RVDT sensors, consider the PXIe-4340.
PXIe-4331 vs PXIe-4330
The PXIe-4331 and PXIe-4330 both provide eight simultaneous, 24-bit bridge input channels with programmable excitation, internal bridge completion, remote sensing and shunt calibration.
The primary difference is maximum sampling rate. The PXIe-4331 supports up to 102.4 kS/s per channel, while the PXIe-4330 supports up to 25.6 kS/s per channel. The PXIe-4331 is better suited to impact, transient and other dynamic measurements.
Why Choose the PXIe-4331?
- 102.4 kS/s high-speed sampling on all eight channels
- 24-bit resolution for low-level bridge signals
- Integrated full-, half- and quarter-bridge support
- Independent programmable excitation per channel
- 120 Ω, 350 Ω and 1 kΩ bridge completion
- Remote sensing for long sensor cables
- Internal and external shunt calibration
Frequently Asked Questions
What is the PXIe-4331 used for?
The PXIe-4331 is used for high-speed measurements from strain gauges, load cells, force sensors, pressure transducers and bridge-based torque sensors.
How many input channels does it provide?
The module provides eight simultaneous strain and bridge input channels.
What is the maximum sampling rate?
The PXIe-4331 supports sampling rates up to 102.4 kS/s per channel.
Which bridge configurations are supported?
The module supports full-, half- and quarter-bridge configurations.
Which quarter-bridge resistances are supported?
Internal completion is available for 120 Ω, 350 Ω and 1 kΩ quarter-bridge sensors.
Does the PXIe-4331 provide sensor excitation?
Yes. Each channel provides independently programmable balanced excitation from 0.625 V to 10 V.
Does it support remote sensing and shunt calibration?
Yes. Each channel supports remote excitation sensing and software-selectable internal or external shunt calibration.
What is the difference between the PXIe-4331 and PXIe-4330?
The PXIe-4331 supports 102.4 kS/s per channel, while the PXIe-4330 supports 25.6 kS/s per channel. Their principal bridge-conditioning features are otherwise similar.
What is the PXIe-4331 part number?
The standard NI part number for the PXIe-4331 is 781345-01.
Request a Quote for the PXIe-4331
Contact us for current availability, lead time and project pricing for the PXIe-4331 High-Speed Strain and Bridge Input Module. We can also help confirm compatible terminal blocks, shielded cables, PXI chassis and related sensor measurement modules.
