Dual Range Thermostats, 150 to 890+ BROIL Dual Range Thermostats The Eaton DRT Thermostats (Also called NaK) were designed for use in selfcleaning ovens. One is the adjustable range used for bake and broil, and the other is the preset clean temperature. Shaft Rotation is clockwise to increase temperature. The DRT thermostat does not have a positive "Off" position. At the lowest setting, 150OF, it is in "warm" position. The Oven is turned on and off by a separate switch. The length of the capillary tube between the switch mechanism and the sensing bulb can be anywhere between 39" and 83". The operating temperature rating of the capillary and sensing bulb is 1000OF ( 5 3 8 OC ) . The sensing bulb in the DRT thermostat is filled with a sodium potassium liquid metal alloy commonly referred to as NaK.