Signal tracer For long pulse trains, a cyclic redundancy check may be calculated and displayed, giving the tech insight into the content of circuits that are switching rapidly. Signal tracer A signal tracer is a piece of electronic test equipment used to troubleshoot radio and other electronic circuitry. Usually a very simple device, it normally provides an amplifier, and a loudspeaker, often battery-powered and packaged into a small, hand-held test probe. An optional diode detector is usually also provided, allowing the detection of amplitude-modulated signals. The technician injects a test signal into the device under test. Then, by using the signal tracer,
PASS device PASS device A PASS device (Personal Alert Safety System) also known as a distress signal unit (DSU) or ADSU (Automatic Distress Signal Unit), is a personal safety device used primarily by firefighters entering a hazardous (IDLH) environment such as a burning building. The PASS device sounds a loud (95 decibel) audible alert to notify others in the area that the firefighter is in distress. On a fireground, the sound of an activated PASS device indicates a true emergency and results in an immediate response to rescue the firefighter(s) in distress. In the United States, the National Fire Protection Association sets