I’m using a radiation survey meter to detect pulses from an x-ray pulse generator, but it doesn’t seem to be detecting anything. Why is that? Posted on April 18, 2018 Due to the short pulse width of some x-ray pulse generators, Geiger Mueller counters cannot detect X-rays emitted. The Ranger, for example, may start to miss counts when a pulse width of the X-ray goes below 40 microseconds. Typically, it is recommended to use ionization chambers for this application.