The NI TB-4353 is an isothermal terminal block engineered to interface directly with the NI PXIe-4353 PXI Temperature Input Module. It minimizes temperature gradients across its terminals to ensure accurate cold-junction compensation (CJC) for thermocouple measurements. The isothermal design optimizes thermal conductivity between thermocouple terminals and integrated CJC channels, enabling high-accuracy temperature acquisition. Eight distributed thermistors measure cold-junction temperatures with precision, while screw-terminal connectivity accommodates standard sensor wiring. The block supports 32 thermocouple input channels and provides 300 V bank isolation for floating thermocouples and common-mode voltages up to 300 V relative to chassis ground.
Technical Specifications
• Supported Module: NI PXIe-4353
• Input Channels: 32 thermocouple inputs
• Cold-Junction Compensation: Eight integrated thermistors distributed across the block
• Isolation: 300 V bank isolation; maximum channel-to-channel voltage ±10 V
• Voltage Range: 10 V maximum (terminal block); ±80 mV thermocouple range (PXIe-4353 module)
• ADC Resolution: 24-bit (PXIe-4353 module)
• Sampling Mode: Scanned sampling
• Open Thermocouple Detection (OTD): Supported; 17 nA input current (OTD enabled), 400 pA (OTD disabled)
• Input Impedance: 20 MΩ differential
• DC Linearity: 20 ppm typical; 60 ppm maximum
• CMRR (Channel-to-COM): 100 dB
• Physical Connector: 96-Pin Female DIN to 67-Pin Female Screw Terminal
– Key Features
• Isothermal construction minimizes measurement errors from temperature gradients
• Eight thermistor channels enable distributed cold-junction compensation
• Screw-terminal interface for reliable signal connectivity
• 300 V bank isolation supports high common-mode voltage applications
• 24-bit resolution supports precision thermocouple measurement
• Open thermocouple detection identifies sensor faults
– Typical Applications
• Multi-channel thermocouple data acquisition systems
• Industrial temperature monitoring and control
• Laboratory thermal measurement and analysis
• Floating thermocouple measurement in high common-mode voltage environments
– Compatibility & Integration
The TB-4353 mounts directly to the PXIe-4353 module within PXI chassis installations. It operates in conjunction with the PXIe-4353’s 24-bit ADC and scanned sampling architecture to deliver synchronized, high-resolution temperature data across 32 channels.
