Ghostbusters have a handheld device that detects “psycho-kinetic energy” (PKE), called, appropriately, the P.K.E. Meter.
Early in the library scene, Spengler is holding the device up in front of his eyes when he explains to Stentz that, “It’s moving.” So theoretically, there is some way by which it helps locate the source of PKE concentration. When we see the front of the device, it’s a bunch of small indictor lights, and impossible to make any sense of what we see there. (In fact, the later scene seems to have the orientation of the device horizontally flipped.) The inscrutability of the interface is fine, diegetically, since it’s a custom device built by scientists for themselves, but as they try and hire new ghostbusters and train them, they’re going to want to think about ease-of-training.
You might think that that green display we see in this first scene is pointing in a cardinal direction, i.e. just behind Spengler, but when we see the same device later, right next to the Keymaster, those indicator lights are spinning around a center that’s off the edge of the screen, so, again, the meaning of these lights is inscrutable.
With a ghost ensconced in a trap, the next step in ghostbusting is to transfer the trap to a containment unit. Let’s look at the interaction.
The containment unit is a large device built into a wall of the old firehouse that serves as the Ghostbusters headquarters. It’s painted a fire-truck red and has two colored bulbs above it. As they approach, the green bulb is lit. It’s got a number of buttons, levers, and cables extending into it. Fortunately for purposes of discussion, Stantz has to explain it to their new employee Winston Zeddmore, and I can just quote him.
“This is where we store all the vapors, entities, and slimers that we trap. Very simple, really. Loaded trap here. Unlock the system…” He grabs the red door lever and cranks it counterclockwise 90 degrees and lowers the door to reveal a slot for the trap.
“Insert the trap,” he continues, and a sucking sound is heard and the green lightbulb goes off and the red lightbulb turns on.
Once ghosts are bound by the streams from the Proton Packs, they can be trapped by a special trap. It has two parts: The trap itself, that is roughly the size of a toaster, and the foot pedal activation switch, which connects to the trap box by a long black cord.
To open the trap, a ghostbuster simply steps on the foot pedal. For a second the trap sparks with some unknown energy and opens to reveal a supernatural light within. Once open, the bound ghost can be manipulated down towards the trap.
The Ghostbusters wear “unlicensed particle accelerators” to shoot a stream of energy from an attached gun. Usefully, this positively-charged stream of energy can bind ghosts. The Pack is the size of a large camper’s backpack and is worn like one. The Proton pack must be turned on and warmed up before use. Its switch, oddly, is on the back, where the user cannot get to it themselves.
When the Ghostbusters are called to the Sedgewick Hotel, they track a ghost called Slimer from his usual haunt on the 12th floor to a ballroom. There Ray dons a pair of asymmetrical goggles that show him information about the “psycho-kinetic energy (PKE) valences” in the area. (The Ghostbusters wiki—and of course there is such a thing—identifies these alternately as paragoggles or ectogoggles.) He uses the goggles to peek from behind a curtain to look for Slimer.
Far be it for this humble blog to try and reverse-engineer what PKE valences actually are, but let’s presume it generally means ghosts and ghost related activity. Here’s an animated gif of the display for your ghostspotting pleasure.
As he scans the room, we see a shot from his perspective. Five outputs augment the ordinary view the googles offer.
1. A plan position indicator (like what you see on a radar) sweeps around and around in the upper left hand corner, but never displays anything (even when Slimer appears.)
Ghostbusters is the story of a group of quirky scientists who start a paranormal pest control service in New York City. Though they struggle initially, the number of infestations mysteriously increases and they begin to capture and incarcerate more and more, leading to national fame. At the same time, the charismatic Ghostbuster Peter Venkman gets romantically involved with Dana, a customer whose case happens to lead them to the center of the mystery of the increasing paranormal activity: the imminent return of an ancient world-destroying demigod called Gozer. Just as the mystery deepens and Dana becomes possessed, they are arrested and their custom-made incarceration device is powered down by an aggressive and suspicious government employee. As a result the device explodes, flooding the city with spooks even while the Ghostbusters, in jail, are helpless to do anything about it. After convincing the mayor that it is in his best interest to release them, the Ghostbusters confront Gozer and use their homemade equipment to send it back to the dimension from which it came, freeing the possessed Dana as well as her neighbor Louis, and saving the day.