**4.1.4 Thermocouple material**

**Thermocouple**: Type E thermocouple has good stability, highest sensitivity among the common metals and thus has high emf output. Based on ASTM set recommended upper temperature limits for various wire sizes, selected diameter for the E type thermocouple is AWG24, 0.51mm diameter. Upper temperature limits for E type is 427oC. Type E has the highest thermopower of 6.317mV/oC in the temperature range (0 -100) oC among any of the standardized types. The thermocouple properties are as shown in Table 2.


Table 2. Thermocouple Material Properties

### **4.1.5 Extension wire**

Thermocouple alloy wire is recommended to be used always to connect a thermocouple sensor to the instrumentation to ensure accurate measurements. Due to the high cost of thermocouple wire, a copper wire was used with assurance of no significant change in the emf produced.
