The P.K.E. Meter functioned just like in the movie, and was used all the time to track down ghosts, demons, and supernatural events. One bad side effect to it was it could explode if exposed to a very big supernatural event. In "Ghosts R Us" the P.K.E. Meter can tell how intelligent a ghost is. A specialty calibrated meter is kept on hand to keep a census on the ghosts in the Containment Unit.