Air Ion Counter: Measures negative & positive ions in the air.  Ghosts generate a high volume of positive ions due to their large amount of electromagnetic discharges.

 

Barometer: Paranormal activity may impact barometric pressure.

 

EMF Detector: Disruptions in electronic fields could mean ghosts.

 

Infrared Thermal Scanner: Find cold spots - saves on time & infrared film.

 

Motion Detectors: Good for sensing movement when there should be none.