Waveform monitor
A waveform monitor (WFM) is a special oscilloscope that is used in professional video technology to measure video levels. With a waveform monitor, the quality of a video signal can be assessed much better than it is on a screen or television . In contrast to the television or monitor image, a waveform monitor shows the electrical voltage of the signal.
What is specific about a WFM compared to a standard oscilloscope is the horizontal and vertical display of the video lines of an image. In the horizontal display, all lines are displayed one above the other, which is primarily used for the overall assessment of the video level. In the vertical display, all lines of a field are displayed side by side, with the displays of both fields being superimposed. This can be used to identify signal errors that are related to the frame rate, e.g. B. also hum interference with analog signals.
Modern devices offer additional measurement options for digital video signals. Most of the waveform monitors used in professional TV broadcasters in Germany come from the American manufacturer Tektronix .
The main area of application is the monitoring of the tolerance limits of luminance and chrominance in video productions or in broadcasting channels. The WFM is also used for troubleshooting, e.g. B. in the case of problems with special switching signals in the blanking interval for analog television broadcasts, such as wide screen signaling for automatic 16: 9 switching in line 23.