NI SCXI-1102 Voltage Input Module

Cold Junction Compensation (CJC): Equipped with a high-precision temperature sensor to real-time compensate for temperature changes at the thermocouple reference junction (cold junction), eliminating measurement errors caused by ambient temperature fluctuations and ensuring temperature measurement accuracy.

Linearity Calibration: For the non-linear characteristics of different thermocouple types (e.g., J, K, T, E, R, S, B, N), linearization processing is performed through a combination of hardware and software, directly outputting voltage signals linearly proportional to temperature.

Wide-Range Gain Adjustment: Supports adjustable gains of 1, 10, 100, and 1000 times, adapting to microvolt-level signals output by thermocouples (e.g., a K-type thermocouple outputs approximately 0mV at 0°C and 4.096mV at 100°C), amplifying them to the optimal sampling range (e.g., ±10V) of DAQ devices.

Electrical Isolation Protection: Built-in 2500V rms electrical isolation between channels and between channels and ground effectively suppresses ground loop noise and common-mode interference, especially suitable for strong electromagnetic interference environments (e.g., near motors and frequency converters).

Filter Function: Integrates a fourth-order Bessel low-pass filter with selectable cutoff frequencies of 10Hz, 100Hz, 1kHz, or 10kHz to filter out high-frequency noise (such as power supply ripple and mechanical vibration interference).

Overload Protection: Withstands ±40V input voltage without damage, adapting to complex wiring environments in industrial fields.

Chassis Adaptability: Supports insertion into 8-slot chassis such as the SCXI-1000. A single module provides 4 independent thermocouple channels, each configurable for different thermocouple types with mutual isolation between channels.

Bus Connection: Seamlessly connects to NI DAQ devices (such as PCIe, USB, and PXI series) via SCXI-1324 cables, supporting plug-and-play and hot swapping for convenient system expansion.

Scenario: Temperature control of heating furnaces in the metallurgical industry

Configuration: SCXI-1000 chassis + SCXI-1102 module (K-type thermocouple) + NI PXIe-6366 DAQ card

Function: Amplifies microvolt signals from thermocouples through cold junction compensation and 1000× gain, eliminates furnace vibration interference with 10Hz low-pass filtering, acquires furnace temperature data in real time, and achieves closed-loop temperature control via LabVIEW with an accuracy of ±1°C.

Scenario: Temperature drift experiment for semiconductor devices

Configuration: SCXI-1102 + T-type thermocouple + chassis + USB-6341 acquisition card

Function: Amplifies thermocouple signals 100 times, directly outputs temperature values using linearization calibration, tests device performance changes in the range of -20°C to 80°C with a constant temperature chamber, and records data in real time via LabVIEW to generate temperature characteristic curves.

Scenario: Transformer winding temperature monitoring

Configuration: SCXI-1102 + multi-channel SCXI chassis + NI PCIe-6353 DAQ card + multiple K-type thermocouples (embedded in windings)

Function: Conditions multiple thermocouple signals, avoids high-voltage equipment interference through 2500V electrical isolation, monitors each winding temperature in real time, and triggers alarms when temperatures exceed thresholds for equipment fault early warning.

Advantage: Mixed installation of SCXI-1102 (thermocouple conditioning), SCXI-1100 (voltage conditioning), SCXI-1180 (current conditioning), and other modules in the SCXI chassis adapts to synchronous acquisition of multiple signal types such as temperature, vibration, and current.

Case: In an automotive engine testing system, simultaneously acquire cylinder temperature (thermocouple signals), vibration acceleration (voltage signals), and fuel injection current (4-20mA signals), achieving unified conditioning through the same chassis to improve system integration.

Function: Using LabVIEW's SCXI driver library, one-click configuration of module parameters (such as thermocouple type, gain, filter frequency), real-time display of temperature waveforms, generation of trend charts, and support for custom algorithm development (such as temperature anomaly warning and historical data tracing).

Wiring Specifications: Use dedicated compensation wires for thermocouple signal lines, ensure correct polarity (+/- poles correspond to module input terminals), and use shielded cables to reduce electromagnetic interference.

Cold Junction Compensation Calibration: When first used or when ambient temperature changes significantly, it is recommended to calibrate cold junction compensation via NI MAX software to ensure temperature measurement accuracy.

Large Temperature Measurement Deviation: Check whether the thermocouple type configuration is correct, whether cold junction compensation is enabled, or calibrate the cold junction compensation offset via NI MAX.

High Signal Noise: Confirm whether the filter frequency setting matches the signal bandwidth (e.g., temperature signals are typically low-frequency, and 10Hz filtering can be set), or check whether the cable shielding layer is well grounded.

Specialization: Specifically designed for thermocouples, supporting direct access to multiple thermocouple types without additional signal conversion circuits;

High Precision: Cold junction compensation accuracy reaches ±0.5°C, and temperature measurement errors after linearization processing are small, suitable for precise temperature monitoring;

Flexibility: Deep integration with NI hardware and LabVIEW software supports multi-channel synchronous acquisition and custom algorithm development, adapting to complex requirements in laboratories and industrial fields.