NI 9231-783610-01C

Description

Detailed parameter table

NI 9231-783610-01C

Product introduction

The NI 9231-783610-01C is a high-precision C Series bridge input module developed by National Instruments (NI), engineered exclusively for strain gauge, load cell, and pressure transducer measurements—filling a critical niche beyond the universal analog input capabilities of the NI 9208. Unlike the NI 9208 (which requires external signal conditioning for bridge sensors), the NI 9231-783610-01C integrates 24-bit delta-sigma ADCs, software-selectable excitation (2.5 V/5 V/10 V), and built-in anti-aliasing filters—delivering turnkey performance for applications where microstrain-level precision is non-negotiable (e.g., aerospace structural testing, automotive crash simulations, civil engineering load monitoring).

In modular DAQ systems, the NI 9231-783610-01C acts as a “precision bridge interface” that eliminates the complexity of external signal conditioning. For example, paired with a NI cRIO-9040 controller in an aircraft wing test rig, it monitors 4 full-bridge strain gauges (sampling at 10 kS/s) to measure stress distribution during simulated flight loads. Its 0.1 µVrms noise floor captures microstrain changes (< 1 µε) that the NI 9208 (limited by 16-bit resolution and lack of bridge conditioning) would miss—critical for validating structural integrity. Unlike standalone strain gauge amplifiers, the NI 9231-783610-01C fits in compact C Series chassis, enabling integration with other modules (e.g., NI 9208 for temperature monitoring) in space-constrained test enclosures.

Core advantages and technical highlights

24-Bit Precision for Microstrain Measurement: The NI 9231-783610-01C’s 24-bit delta-sigma ADC and < 0.1 µVrms noise floor enable measurements down to ±1 microstrain (µε)—far beyond the NI 9208’s 16-bit resolution (limited to ~10 µε for strain applications). In a civil engineering lab, for instance, it monitors a concrete beam’s deflection via 4 quarter-bridge strain gauges: the module detects 0.5 µε changes as the beam is loaded, allowing engineers to calculate modulus of elasticity with ±0.01% accuracy. This precision is essential for structural health monitoring, where early detection of microstrain anomalies can prevent catastrophic failures.

Built-In Bridge Conditioning Reduces System Complexity: Unlike the NI 9208, which requires external amplifiers, excitation sources, and filter modules for bridge sensors, the NI 9231-783610-01C integrates all necessary conditioning: software-selectable excitation (2.5 V/5 V/10 V), lead-wire compensation, and anti-aliasing filters. A automotive manufacturer uses this to streamline crash test setups: 8 NI 9231-783610-01C modules (in a NI cDAQ-9178 chassis) monitor 32 load cells in a crash dummy—each module handles excitation and filtering, eliminating 32 external amplifiers and reducing wiring by 70%. This integration also improves measurement stability, as internal conditioning minimizes noise from loose connections or external interference.

Flexible Bridge Compatibility for Diverse Sensors: The NI 9231-783610-01C supports full-bridge, half-bridge, and quarter-bridge configurations (120 Ω/350 Ω) with software-selectable completion resistors—adapting to 90% of industrial bridge sensors (strain gauges, load cells, pressure transducers). A manufacturing plant, for example, uses it to measure: 1) full-bridge load cells (350 Ω) for press force (5 V excitation), 2) half-bridge strain gauges (120 Ω) for shaft torque (2.5 V excitation), and 3) quarter-bridge pressure transducers (350 Ω) for hydraulic pressure (10 V excitation)—all with one module type. The NI 9208 would require custom resistor networks and external excitation for each sensor type, increasing cost and failure points.

Seamless Synchronization with C Series Ecosystem: Like the NI 9208, the NI 9231-783610-01C synchronizes with other C Series modules via the chassis backplane—enabling correlated measurements of strain, temperature, and voltage. In a wind turbine test, the NI 9231-783610-01C (strain) and NI 9208 (temperature) are synchronized via a NI cRIO-9040’s FPGA, ensuring strain data is time-aligned with gearbox temperature readings (±10 ns latency). This correlation lets engineers isolate strain changes caused by temperature drift, improving the accuracy of fatigue life calculations. The NI 9231-783610-01C also supports NI-TClk for multi-chassis synchronization, scaling to large test systems (e.g., 100+ strain gauges across 25 modules).

Typical application scenarios

In aerospace structural testing, the NI 9231-783610-01C validates composite aircraft components. Paired with a NI cRIO-9040 controller, it monitors 4 full-bridge strain gauges (attached to a composite wing panel) at 50 kS/s—capturing microstrain responses to dynamic loads (e.g., turbulence simulations). Its 100 dB CMRR rejects electromagnetic interference from test rig motors, ensuring clean strain data, while built-in lead-wire compensation corrects for 10-meter cable resistance (common in large test setups). The NI cRIO-9040 uses this data to adjust hydraulic actuators in real time, maintaining load profiles within ±1% of target—something the NI 9208 could not achieve without external conditioning, which would introduce latency and noise.

In industrial manufacturing, the NI 9231-783610-01C ensures press machine precision. A metal stamping plant uses the module with a NI cDAQ-9185 Ethernet chassis to measure the force of a 500-ton press via a 350 Ω full-bridge load cell. The NI 9231-783610-01C’s 5 V excitation and 24-bit resolution track force changes from 0 to 500 tons with ±50 lb accuracy—critical for ensuring consistent part quality (e.g., avoiding over-stamping or under-stamping). Its Ethernet connectivity streams force data to a factory MES system for real-time monitoring, while historical data logs (stored via DMA) enable predictive maintenance (e.g., detecting press wear via gradual force drift). Unlike the NI 9208, which would require a separate amplifier and signal conditioner, the NI 9231-783610-01C provides a compact, integrated solution.

Related model recommendations

NI cRIO-9040: An embedded C Series controller that pairs with the NI 9231-783610-01C. The NI cRIO-9040 provides real-time FPGA processing for synchronized strain/temperature measurements, while the module captures bridge sensor data—ideal for rugged structural testing (e.g., aerospace, civil engineering).

NI cDAQ-9178: An 8-slot CompactDAQ chassis compatible with the NI 9231-783610-01C. It supports up to 8 modules (32 strain channels) and USB/Ethernet connectivity—enabling portable or fixed strain monitoring systems (e.g., automotive crash tests, factory press monitoring).

NI 9208: A universal analog input module complementary to the NI 9231-783610-01C. The NI 9231-783610-01C measures strain/force, while the NI 9208 monitors temperature (thermocouples/RTDs) and voltage—providing correlated multi-sensor data (e.g., wind turbine strain + gearbox temperature).

NI TB-9231: A terminal block included with the NI 9231-783610-01C, designed for bridge sensor wiring. It includes labeled terminals for excitation, sense, and signal lines, plus built-in protection against reverse polarity—simplifying strain gauge/load cell installation.

NI 9949: A shielded twisted-pair cable for the NI 9231-783610-01C, connecting the module to the TB-9231. It reduces noise in industrial environments (e.g., near motors or power lines) and supports lead-wire compensation—preserving the module’s microstrain precision.

NI-DAQmx Driver: The core driver for the NI 9231-783610-01C, enabling configuration of bridge type, excitation voltage, and sampling rate. It includes strain/force scaling libraries (e.g., converting ADC counts to µε or pounds-force) to simplify data analysis.

NI LabVIEW 2024: Essential software for programming the NI 9231-783610-01C. It includes pre-built VIs for bridge calibration, real-time strain visualization, and fatigue analysis—reducing development time for structural testing applications by 60%.

NI 9172: A NIST-traceable calibration chassis used to verify the NI 9231-783610-01C’s accuracy. When paired with a strain calibrator adapter, it generates known strain values to validate the module’s ±0.01% reading accuracy annually.

Installation, commissioning and maintenance instructions

Installation preparation: Before installing the NI 9231-783610-01C, power off the C Series chassis (e.g., NI cRIO-9040, NI cDAQ-9178) and wear an ESD wristband (±15 kV) to protect the module’s precision ADCs. Align the module with an empty chassis slot, ensuring guide pins match the slot’s grooves, then push firmly until it clicks into place. Secure it with the chassis’ locking mechanism (if available). Connect the TB-9231 terminal block to the module using the included NI 9949 shielded cable. Wire bridge sensors: for full-bridge strain gauges, connect excitation (+/-), signal (+/-), and sense (+/-) lines to the terminal block; use the module’s software-selectable completion resistors for half/quarter-bridges. Power on the chassis and host PC, install the latest NI-DAQmx driver and LabVIEW, then use NI Measurement & Automation Explorer (MAX) to detect the NI 9231-783610-01C. Run a “Bridge Calibration Test” in MAX (using a known strain source or shunt resistor) to verify accuracy.

Maintenance suggestions: Calibrate the NI 9231-783610-01C annually using a NIST-traceable strain calibrator (e.g., NI 9172 with adapter) to maintain ±0.01% reading accuracy. Inspect the terminal block and shielded cables quarterly: tighten loose screws (to prevent resistance-induced errors) and clean terminals with isopropyl alcohol (99.9% purity) to remove oxidation. If the module reports noisy strain data, check for damaged cable shielding or ungrounded sensors—replace the NI 9949 cable if shielding is compromised. Avoid exposing the module to temperatures above 70 °C or humidity above 95%—extreme conditions can degrade the delta-sigma ADC and excitation circuitry. When replacing the module, power off the chassis first to prevent backplane damage, and re-calibrate sensor scaling in software to match the new module’s offset/gain.

Service and guarantee commitment

National Instruments (NI) provides a 2-year standard warranty for the NI 9231-783610-01C, covering defects in materials and workmanship—including the 24-bit ADC, excitation circuit, and bridge conditioning components. For extended protection, the ServicePlus Precision Plan extends coverage to 5 years, including annual factory calibration (traceable to NIST) for strain/force accuracy, priority technical support (2-hour response time for aerospace/automotive customers), and expedited repairs (turnaround time < 3 business days).

NI’s global technical team includes bridge sensor specialists, offering 24/7 support for the NI 9231-783610-01C—assisting with bridge configuration, noise reduction, and software scaling (e.g., converting ADC counts to µε). Customers gain free access to exclusive resources: application notes on strain gauge testing with the NI 9231-783610-01C, LabVIEW example code for fatigue analysis, and a user community for sharing bridge sensor best practices. For out-of-warranty repairs, NI’s Precision Bridge Module Restore Service replaces aged components (e.g., delta-sigma ADC, excitation voltage regulator) and verifies microstrain precision—restoring the NI 9231-783610-01C to factory specs. This commitment reflects NI’s confidence in the module’s durability and dedication to supporting users’ high-precision bridge-based measurement needs.