... Connect to the AV 220 power source ,open the power switch.The PV display window will display the room temperature and ... protection function,when the thermocouple is not connected well or switch off , the display window will show "hhhh” ,when green ... 2/1Room tem- 999°C≤1500Professional PID self adjustment ,slight touch switch ,double screen display ,thermocouple K temperature sense ,controlled silicon ...