Crossunder,
You may find the
AIRCRAFT SERIOUS INCIDENT INVESTIGATION REPORT - Bombardier DHC-8-402 registration JA848C helpful...
"ITT: Inter-Turbine Temperature or Indicated Turbine Temperature" (page 4 (pdf reader))
Paragraph 2.1.1 - footnote *1 "Turbine temperature refers to the combustion gas temperature near the inter-turbine and is calculated based on the temperatures sensed by the multiple sensors installed on the exhaust duct." (page 9 (pdf reader) page 2 of report)
Figure 12 illustrates 8 items in the exhaust duct, that I think are the associated thermocouples (page 47 (pdf reader) page 40 of report)
If you have local (or PWC portal) access to the Aircraft FIM, the report indicates, page 23 (pdf reader) page 16 of report, "TASK 71-00-00-810-814 Engine #1 (#2), Sudden Increase/abnormal ITT-Fault Isolation" and "Is the indicated turbine temperature (ITT) system correct (Refer to AMM TASK 77-21-01-720-801)?"