Prüfsignal

Prüfsignal is a term used in German-language technical literature to denote a signal that is applied to a system under test in order to verify its proper function or to characterize its performance. The Prüfsignal is intentionally defined with known properties, so that the observed response can be compared with reference data. It is generated by test equipment and injected at the input of the device or at a specified port, while the resulting output is recorded for analysis. The concept is used across electronics, telecommunications, measurement technology, control engineering, and related fields, including railway signaling and medical instrumentation.

The primary purpose of a Prüfsignal is to enable calibration, validation, fault detection, and performance characterization. It helps determine a system’s gain, bandwidth, phase response, linearity, distortion, and noise characteristics. By providing a controlled stimulus, Prüfsignale reduce the influence of external variables and allow repeatable measurements. In practice, the Prüfsignal may also serve as a diagnostic indicator, for example to verify that signal paths are intact or that timing and synchronization are correct.

Common forms of Prüfsignale include time-domain signals such as impulses, steps, sine waves, square waves, and ramps; frequency-domain signals such as sweeps and chirps; pseudo-random binary sequences (PRBS); and noise signals (white or colored). In digital and protocol-based systems, predefined sequences or frames can act as Prüfsignale. The exact choice depends on the device under test and the aspects to be assessed.

In summary, a Prüfsignal is a predefined, known stimulus used to test, calibrate, and validate the performance of a system or component. See also test signal, calibration, and impulse response.