DFP-02 Proportional bias device is an auxiliary unit of DDZ-Ⅱ instrument. There are three independent channels and every channel can do positive and negative bias and magnify to input 0～10mA signal. In addition, to change different amplification can convert 4～20mA signal to 0～10mA signal. In regulating system, if you need one regulator to drive more valves to work and every valve’s beginning and closing speed are different, the proportional bias device is a good distributor. According to load resistance, one regulator can have 7 isolation channels to control 7 valves.