On my PHMP/PHMP-4 how is the displayed temperature calculated?

The temperature of the lid is calculated as follows:
For the temperature greater than 30 degrees, t(lid)=t(set)/16+t(set)

The actual temperature on the display is shown as the temperature of the bottom heater, actually when you set the temperature, you set the temperature on the bottom and the lid heater temperature is regulated by the program.
If one of the heaters is not working, then the actual temperature on the display will be empty. There is no special alert or sound signal to inform you that the heating is ON, but temperature will not be increasing.

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