Status sem1636 4 to 20ma loop powered dual alarm relay trip amplifier status instruments sem1636 this dual trip amplifier monitors a 4 to 20ma loop and provides two independent co trip contacts that are set to alarm at any point in the 4 to 20ma range the unit requires no additional external power as power is provided by the 4 to 20ma loop the outputs from the dual relays are independently configured for action set point and dead band and six actions are provided normal and inverted low