The National Instruments SCXI-1303 is an advanced isothermal terminal block designed for high-precision thermocouple temperature measurement applications. Recommended for use with SCXI modules such as the SCXI-1100, SCXI-1102, SCXI-1102B, and SCXI-1102C, this terminal block features 32 channels and provides 78 screw terminals for straightforward signal connectivity. The SCXI-1303 integrates a highly accurate thermistor cold-junction temperature sensor, ensuring minimal thermal gradients across the terminals during thermocouple measurements. This model includes essential features such as open thermocouple detection and signal ground referencing, with the ability to saturate the channel by applying a +5 V bias to detect open thermocouples. It accommodates both 10 Ω and 10 MΩ bias resistors, making it versatile for use with various SCXI modules. The cold-junction sensor offers accuracy of 0.5 °C from 15 to 35 °C and 0.9 °C in the range of 0 to 15 °C and 35 to 55 °C, with an output voltage ranging from 1.91 V to 0.58 V across this temperature span. The SCXI-1303 is supported by NI-DAQ driver software and is compatible with LabVIEW and LabWindows/CVI development environments. Although the SCXI-1303 has been designated as obsolete, it remains available for purchase and repair through Apex Waves.