Zhonghe XJZC-03A/Q Speed & Impact Monitoring Instrument | Turbine Overspeed Protection Monitor The XJZC-03A/Q Speed/Trip Bolt Monitor measures rotational speed while simultaneously receiving two emergency trip signals. It is designed for the continuous monitoring and measurement of rotational speeds in rotating machinery and records the speeds at which two emergency trip events occur. Product Overview The XJZC-03A/Q monitor accepts two channels of discrete (switch) signals