Modern signals in for instance wireless communication systems and radars use very complex modulation with high peakto- average ratio. Other signals, such as in reverberation chambers with mode stirring, vary very fast with a high dynamic range. Conventional probes, using thermocouples or diode detection, show wrong measurement results due to the slow response time of the detector or the analog-to-digital converter, or the limited dynamic range of the detector. These response times are often missing in data sheets, and in case they are listed the numbers are not always correct. This paper describes pulse response experiments performed with a radiation hazard meter, a diode detector, several commercial field strength probes and probes using l...