Investigation on Reading Discrepancy of Type T and Type J Thermocouples

Thermocouples are widely used in industry for temperature measurement due to their high accuracy and sensitivity. However, thermocouples can act as a heatsink or a heat spreader when attached onto the top surface of small components like Voltage Regulator Modules (VRM), Capacitors, Platform Controller Hubs (PCH), and etcetera. This could alter cooling conditions of components, consequently leading to temperature measurement discrepancy on these modules. This discrepancy could be more obvious for smaller components without a heatsink or heat spreader attached. Also, the potential discrepancy relies on not only package material of components but the type of thermocouples considering the different thermocouple wire composition. This paper focuses on investigating temperature measurement discrepancies for 36-gauge type T and 36-gauge type J thermocouples on components without heatsinks or heat spreaders attached. Analysis is performed with both numerical simulation modeling using the CFD tool FloTHERM and actual testing measurements based on Intel commercial server products.