>In short, boiling water temperature plateaus due to the latent heat of vaporization. When the water is gone the temperature of the pot starts to rise. The rice

>In short, boiling water temperature plateaus due to the latent heat of vaporization. When the water is gone the temperature of the pot starts to rise. The rice cooker uses this principle to control the switch. This is true for a lot of appliances: water boiler, coffee percolator, drip coffee maker, etc. They have to be reliable enough that you can have a 1000W+ heater right next ABS plastic and not have problems with millions of units.