4202APC1/4201APC2/4202APF2數字控制器OMEGA歐米茄Model 4201A Single Setpoint Proportional Controller This versatile digital controller can be operated as a proportional controller with the adjustable bandwidth up to 3% of full span. The setpoint temperature is always available. Simply push the spring-loaded setpoint switch to the right, and the setpoint is digitally displayed. To change the setpoint, with the switch deflected to the right, adjust the knob to the right of the switch until you get the desired reading. The standard Model 4201 has an internal SPDT relay (7 amp resistive at 120 Vac). This model is also available with optional Triac or 4 to 20 mA output in place of the relay. See Options and Specifications for more information.